added fix, that if the L2 goes down on ptp-NT that we reinitialize the NT...

added fix, that if the L2 goes down on ptp-NT that we reinitialize the NT Library. Also if we have no ntflags, we don't pass the filename to the debug routines of mISDNuser.

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@36376 65c4cc65-6c06-0410-ace0-fbb531ad65f3