Remove a noisy debug message from bridging code.

This particular debug message, during a stress test, was logged so
often that it appeared that there may be a memory leak in the logger
code. In actuality, there was no memory leak, but the logger thread
was having a hard time keeping up with the demands of the rest of the
system.

Since this debug message has no value at all, the best way to fix the
problem was to just remove the message.

(closes issue AST-1225)
reported by John Bigelow

Patches:
	spammy_log.diff uploaded by Mark Michelson (License #5049)
........

Merged revisions 401364 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@401365 65c4cc65-6c06-0410-ace0-fbb531ad65f3