Misc (re #1151): respond incoming re-INVITE with 491 instead of 500 if we are waiting for response for our outgoing re-INVITE. If we are currently processing another incoming re-INVITE, then respond with 500, as it is now

git-svn-id: https://svn.pjsip.org/repos/pjproject/trunk@3385 74dad513-b988-da41-8d7b-12977e46ad98
1 file changed