Ignore validator warning for no_u_turn where from and to

[planemad]

What steps will reproduce the problem?

1. Open no_u_turn relation in JOSM ​https://www.openstreetmap.org/relation/6496407#map=19/37.76366/-122.47627
2. Run validator

What is the expected result?

No warnings

What happens instead?

Warning that the same object has both the from and to role. This is valid for a no-u-turn on a two way road segment.

Please provide any additional information below. Attach a screenshot if possible.

URL:http://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2017-07-30 17:07:42 +0200 (Sun, 30 Jul 2017)
Build-Date:2017-07-30 15:14:00
Revision:12542
Relative:URL: ^/trunk

Identification: JOSM/1.5 (12542 en) Mac OS X 10.12.5
OS Build number: Mac OS X 10.12.5 (16F73)
Memory Usage: 493 MB / 1820 MB (82 MB allocated, but free)
Java version: 1.8.0_131-b11, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Screen: Display 69731840 1280x800
Maximum Screen Size: 1280x800
VM arguments: [-Djava.security.policy=file:<java.home>/lib/security/javaws.policy, -DtrustProxy=true, -Djnlpx.home=<java.home>/bin, -Djava.security.manager, -Djnlpx.origFilenameArg=${HOME}/Library/Application Support/Oracle/Java/Deployment/cache/6.0/56/1ee8cfb8-627fd6bf, -Djnlpx.remove=false, -Dsun.awt.warmup=true, -Djava.util.Arrays.useLegacyMergeSort=true, -Dmacosx.jnlpx.dock.name=JOSM, -Dmacosx.jnlpx.dock.icon=${HOME}/Library/Application Support/Oracle/Java/Deployment/cache/6.0/16/47ee53d0-70f4e903.icns, -Djnlp.application.href=https://josm.openstreetmap.de/download/josm.jnlp , -Djnlpx.jvm="<java.home>/bin/java"]
Dataset consistency test: No problems found

Plugins:
+ AddrInterpolation (33160)
+ BuildingGeneralization (1010)
+ CADTools (1007)
+ CommandLine (33368)
+ Create_grid_of_ways (32699)
+ FastDraw (33182)
+ FixAddresses (33182)
+ HouseNumberTaggingTool (33160)
+ ImproveWay (12)
+ Mapillary (v1.5.5)
+ PicLayer (33385)
+ apache-commons (32994)
+ apache-http (32699)
+ auto_tools (1494971731)
+ buildings_tools (33004)
+ conflation (0.5.4)
+ ejml (32680)
+ ext_tools (33004)
+ geojson (52)
+ geotools (33380)
+ graphview (33004)
+ imagery_offset_db (33316)
+ jogl (1.0.46)
+ jts (32699)
+ kendzi3d-resources (0.0.1)
+ lakewalker (33161)
+ log4j (32699)
+ merge-overlap (33436)
+ opendata (33438)
+ public_transport (33166)
+ rasterfilters (33269)
+ reltoolbox (33311)
+ reverter (33088)
+ scripting (30768)
+ terracer (33088)
+ turnlanes (33294)
+ turnrestrictions (33088)
+ undelete (33480)
+ utilsplugin2 (33328)
+ wikipedia (33288)

Tagging presets:
+ https://josm.openstreetmap.de/josmfile?page=Presets/LaneAttributes&zip=1
+ https://josm.openstreetmap.de/josmfile?page=Presets/Quick-highways&zip=1

Map paint styles:
- https://raw.githubusercontent.com/Andygol/josm-styles/master/created_in_2015.mapcss
- ${HOME}/GitHub/mapbox/mapping/JOSM/data-qa.mapcss
+ https://josm.openstreetmap.de/josmfile?page=Styles/Lane_and_Road_Attributes&zip=1
- https://josm.openstreetmap.de/josmfile?page=Styles/Coloured_buildings&zip=1
- ${HOME}/GitHub/Mapbox/mapping/JOSM/mapcss/destination.mapcss
- https://raw.githubusercontent.com/mapbox/mapping/master/JOSM/data-qa.mapcss
- https://raw.githubusercontent.com/mapbox/mapping/master/JOSM/styles/road-areas.mapcss
+ ${HOME}/Downloads/road-areas.mapcss

Last errors/warnings:
- W: java.net.SocketTimeoutException: Read timed out
- W: Could not read from URL https://a.mapillary.com/v3/sequences?client_id=T1Fzd20xZjdtR0s1VDk5OFNIOXpYdzoxNDYyOGRkYzUyYTFiMzgz&bbox=-122.411004%2C37.7912638%2C-122.4078805%2C37.7929905!: java.io.IOException: Server returned HTTP response code: 503 for URL: https://a.mapillary.com/v3/sequences?client_id=T1Fzd20xZjdtR0s1VDk5OFNIOXpYdzoxNDYyOGRkYzUyYTFiMzgz&bbox=-122.411004%2C37.7912638%2C-122.4078805%2C37.7929905
- W: Could not read from URL https://a.mapillary.com/v3/detections?client_id=T1Fzd20xZjdtR0s1VDk5OFNIOXpYdzoxNDYyOGRkYzUyYTFiMzgz&bbox=-122.411004%2C37.7912638%2C-122.4078805%2C37.7929905!: java.io.IOException: Server returned HTTP response code: 503 for URL: https://a.mapillary.com/v3/detections?client_id=T1Fzd20xZjdtR0s1VDk5OFNIOXpYdzoxNDYyOGRkYzUyYTFiMzgz&bbox=-122.411004%2C37.7912638%2C-122.4078805%2C37.7929905
- W: Could not read from URL https://a.mapillary.com/v3/images?client_id=T1Fzd20xZjdtR0s1VDk5OFNIOXpYdzoxNDYyOGRkYzUyYTFiMzgz&bbox=-122.411004%2C37.7912638%2C-122.4078805%2C37.7929905!: java.io.IOException: Server returned HTTP response code: 503 for URL: https://a.mapillary.com/v3/images?client_id=T1Fzd20xZjdtR0s1VDk5OFNIOXpYdzoxNDYyOGRkYzUyYTFiMzgz&bbox=-122.411004%2C37.7912638%2C-122.4078805%2C37.7929905
- W: java.net.SocketTimeoutException: Read timed out
- W: java.net.SocketTimeoutException: Read timed out
- W: java.net.SocketTimeoutException: Read timed out
- W: java.net.SocketTimeoutException: Read timed out
- W: java.net.SocketTimeoutException: Read timed out
- W: java.net.SocketTimeoutException: Read timed out

[naoliv]

The warning is caused by not properly supporting/understanding the conditional restriction.
ie, with restriction:conditional=no_u_turn @ (08:00-09:00,14:00-15:00) (while with a simple restriction=no_u_turn we don't have a warning anymore¹)

¹ just an informational message (in Other), that helps a lot in cleaning this mess ​https://github.com/openstreetmap/iD/issues/2527