'G' - ungluing building - creates unconnected node

[Larry0ua]

The bug is that sometimes JOSM produces duplicated single nodes after ungluing lines. see example and steps.

Steps to reproduce the bug:

1. Download some location with two glued buildings where start-end point of some of the building is at their glying line.
2. Select building which contains that start-end point.
3. Press 'G' to unglue the building.
4. Check that we have unnecessary unconnected node after the operation.

Example:

1. Download location ​http://api.openstreetmap.org/api/0.6/map?bbox=25.9392089,48.2908923,25.9400082,48.2913563
2. Verify that validator plugin does not warn about any duplicated node - run validator.
3. Select house with number 24
4. Press 'G'
5. Move house 24 and 26 - see that there is unconnected node. It was created during 'G' operation. You also can run validator and receive error - there are duplicated nodes (do it before moving buildings)
6. Do not upload your changes, of course :)

[bastiK]

In [4487/josm]:

fixed #6848 - 'G' - ungluing building - creates unconnected node