letting the original krauss model use its own followSpeed as insertionFollowSpeed. refs #1414 (reverting test result for kraussOrig1 to [16495])

git-svn-id: http://svn.code.sf.net/p/sumo/code/trunk/sumo@16957 29f149b2-0c63-11e1-8f5c-a347f6a9acd0