Fix typo in confbridge.conf.sample

The denoise filter requires func_speex, not codec_speex.  Fix this in the
description of the denoise=yes option in confbridge.conf.



git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/11@398820 f38db490-d61c-443f-a65b-d21fe96a405b