re-enable external_sip_uri and use domain_exists to tell if its really an external domain

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@9973 d0543943-73ff-0310-b7d9-9358b9ac24b2

conf/dialplan/default.xml

@@ -98,16 +98,15 @@
       </condition>
     </extension>
 
-    <!-- If to_host and from_host differ this is an external sip URI so lets send it out. -->
-    <!--
+    <!-- If sip_req_host is not a local domain them this has to be an external sip uri -->
     <extension name="external_sip_uri" continue="true">
       <condition field="source" expression="mod_sofia"/>
       <condition field="${outside_call}" expression="^$"/>
-      <condition field="${sip_req_host}" expression="${sip_from_host}">
+      <condition field="${domain_exists(${sip_req_host})}" expression="true">
 	<anti-action application="bridge" data="sofia/${use_profile}/${sip_to_uri}"/>
       </condition>
     </extension>
-    -->
+
     <!--
 	snom button demo, call 9000 to make button 2 mapped to transfer the current call to a conference
     -->