Fix segfault in mod_conference

This was introduced by commit a4408e62a6ca1bc36e26109396af332d05fae812.

FS-5612 --resolve
FS-5700 --resolve
FS-5528 --resolve
FS-5708 --resolve
FS-5709 --resolve
Revert FS-5708 ; build issues

This reverts commit 77d0ee21b2bf64d16e665ef43acfdda98f3514b3.
FS-5708 --resolve
FS-5164 --resolve add support for setting user variables w/ skinny
FS-5164 - fix segv on ring handling due to listener not being defined
mod_rayo: Remove compensation for Punchblock Rayo spec incompatibility
mod_rayo: use XMPP URI instead of FS UUID for join/unjoin
Merge branch 'v1.2.stable' of git://git.freeswitch.org/freeswitch into v1.2.stable