Avoid unnecessary WARNING message

Add AST_CONTROL_UPDATE_RTP_PEER frame to be ignored here to avoid
displaying a WARNING message.

(closes issue ASTERISK-18610)
 Patch by: Kristijan_Vrban
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Merged revisions 340878 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 340879 from http://svn.asterisk.org/svn/asterisk/branches/10


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@340880 65c4cc65-6c06-0410-ace0-fbb531ad65f3