mark gk-interface mandatory.

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@15229 d0543943-73ff-0310-b7d9-9358b9ac24b2

src/mod/endpoints/mod_h323/h323.conf.xml

@@ -6,7 +6,7 @@
     <param name="codec-prefs" value="PCMA,GSM,G729,G726"/>
     <param name="gk-address" value=""/>    <!-- empty to disable, "*" to search LAN -->
     <param name="gk-identifer" value=""/>  <!-- optional name of gk -->
-    <param name="gk-interface" value=""/>  <!-- optional listener interface name -->
+    <param name="gk-interface" value=""/>  <!-- mandatory listener interface name -->
     <param name="gk-retry" value="30"/>  <!-- optional GK register retry timer -->
     <param name="faststart" value="true"/>  <!-- optional -->
     <param name="h245tunneling" value="true"/>  <!-- optional -->