add docs

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@14204 d0543943-73ff-0310-b7d9-9358b9ac24b2

conf/vars.xml

@@ -183,7 +183,7 @@
   <X-PRE-PROCESS cmd="set" data="default_provider_contact=5000"/>
 
   <!--
-      SIP and TLS settings.
+      SIP and TLS settings. http://wiki.freeswitch.org/wiki/Tls
   -->
   <X-PRE-PROCESS cmd="set" data="sip_tls_version=tlsv1"/>