alembic: Fix alembic migration for 'moh_passthrough' option in res_pjsip.


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@428223 f38db490-d61c-443f-a65b-d21fe96a405b
res_pjsip_sdp_rtp: Add support for optimistic SRTP.

Optimistic SRTP is the ability to enable SRTP but not have it be
a fatal requirement. If SRTP can be used it will be, if not it won't be.
This gives you a better chance of using it without having your sessions
fail when it can't be.

Encrypt all the things!

Review: https://reviewboard.asterisk.org/r/3992/
........

Merged revisions 428222 from http://svn.asterisk.org/svn/asterisk/branches/13


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@428224 f38db490-d61c-443f-a65b-d21fe96a405b