fix #1482

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@17452 29f149b2-0c63-11e1-8f5c-a347f6a9acd0
fixing connection building when connections are deleted refs #1457. Should do another OSM test

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@17453 29f149b2-0c63-11e1-8f5c-a347f6a9acd0