fix a bug introduced in 15187 that scrambled the flags and

among other things prevented proper handling of NAT.
Don't think it exist in 1.2 but be careful if 15187 is merged.



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@15744 65c4cc65-6c06-0410-ace0-fbb531ad65f3