When conf_mute_on_entry is switched on, show this in debug when creating the conference and also update conflist to reflect this state (Reported by Alena Juk)

git-svn-id: https://svn.code.sf.net/p/chan-sccp-b/code/trunk@5274 43c1dc8c-776e-4df2-8ef1-6e829299be21