fix bind_server_ip since its only used in dingaling and NOT sofia

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@9551 d0543943-73ff-0310-b7d9-9358b9ac24b2

conf/vars.xml

@@ -65,7 +65,7 @@
        This determines an ip address available on this host to bind.
        If you are separating RTP and SIP traffic, you will want to have
        use different addresses where this variable appears.
-       Used by: sofia.conf.xml dingaling.conf.xml
+       Used by: dingaling.conf.xml
   -->
   <X-PRE-PROCESS cmd="set" data="bind_server_ip=auto"/>
   <!-- external_rtp_ip