josm freezes or hard quits occasionally when using tag help

[cmuelle8]

What steps will reproduce the problem?

1. open josm (ubuntu/openjdk8 env)
2. retrieve data
3. use "Go to OSM wiki for help (F1) in context menu of tag list

What is the expected result?

Page should open up in browser.

What happens instead?

JOSM freezes, Strg+C in console won't help, the process needs to be "killed". Last messages on the console is the URL about to be opened (the resolved one). Sometimes JOSM hard quits, with the console printing

INFO: HEAD https://wiki.openstreetmap.org/wiki/De:Tag:waterway=fish_pass -> 301
INFO: Herunterladen umgelenkt auf 'https://wiki.openstreetmap.org/wiki/DE:Tag:waterway%3Dfish_pass'
INFO: HEAD https://wiki.openstreetmap.org/wiki/DE:Tag:waterway%3Dfish_pass -> 200
INFO: Öffne URL: https://wiki.openstreetmap.org/wiki/De:Tag:waterway=fish_pass
java: Fatal IO error 11 (Die Ressource ist zur Zeit nicht verfügbar) on X server :0.

In the freezing case, just the last line is missing.

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

In the past this feature worked reliably. Since the URL handling code was changed in the past (http to https), may be other sections have changed as well, unintentionally triggering the behavior above?

Build-Date:2016-01-06 15:46:18
Revision:9328
Is-Local-Build:true

Identification: JOSM/1.5 (9328 SVN de) Linux Ubuntu 15.10
Memory Usage: 532 MB / 1609 MB (111 MB allocated, but free)
Java version: 1.8.0_66-internal, Oracle Corporation, OpenJDK 64-Bit Server VM
Dataset consistency test: No problems found

Plugins:
- PicLayer (31895)
- RoadSigns (31895)
- alignways (31895)
- apache-commons (31895)
- editgpx (31106)
- imagery_offset_db (31895)
- kendzi3d (1.0.189)
- kendzi3d-jogl (41)
- kendzi3d-resources (0.0.1)
- log4j (31895)
- openvisible (31106)
- pbf (31772)
- photo_geotagging (31895)
- photoadjust (31953)
- poly (31772)
- print (31895)
- reverter (31897)
- turnlanes (31772)
- turnrestrictions (31895)
- utilsplugin2 (31895)
- wikipedia (31917)