fixed bug that was preventing follower vehicles from behing returned to the laneChanger (technically that was safe since it only happened if those vehicles were outside the critical distance but it prevented them from being subject to speed requests).

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@17082 29f149b2-0c63-11e1-8f5c-a347f6a9acd0