[Patch] Bug when keeping local (my) value in property conflict resolution

[Gubaer]

1	JOSM 1	Server	JOSM 2
2	Create amenity=biergarten testkey=value1 and upload	amenity=biergarten testkey=value1 id=1 version=1
3	amenity=biergarten testkey=value1 id=1 version=1		Downlad amenity=biergarten testkey=value1 id=1 version=1
4	Update amenity=biergarten testkey=value2 id=1 version=1 and upload	amenity=biergarten testkey=value2 id=1 version=2
5	amenity=biergarten testkey=value2 version=2		Update amenity=biergarten testkey=value3 version=1
6	amenity=biergarten testkey=value2 version=2		Download and merge results in a conflict as expected
7	Resolve conflict and decide to keep my value, i.e. testkey=value3
8	Upload results in 409 conflict. Local version is still version 1

The problem is in step 7. If the user decides to keep his value the local version is not updated to the higher version from the server.

See patch for a fix.