Changed the "busy-level" option in sip.conf to "busylevel" to be more parallel

with the SIPPEER() argument of the same name. The deprecation procedure is not
being used here since this is a trunk-only option.

(closes issue #11307, reported by pj, patched by me)



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@89441 65c4cc65-6c06-0410-ace0-fbb531ad65f3