Fix an issue where outgoing calls would fail to establish audio due to ICE negotiation failures.

This change removes the requirement for ufrag and pwd in the transport stanza and also
makes us the controlling agent.

(closes issue ASTERISK-20554)
Reported by: mmichelson

........

Merged revisions 374850 from http://svn.asterisk.org/svn/asterisk/branches/11


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@374852 65c4cc65-6c06-0410-ace0-fbb531ad65f3