remove duplicate "rtp-timeout-sec"

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@13670 d0543943-73ff-0310-b7d9-9358b9ac24b2

conf/sip_profiles/external.xml

@@ -49,7 +49,6 @@
     <param name="inbound-codec-negotiation" value="generous"/>
     <param name="nonce-ttl" value="60"/>
     <param name="auth-calls" value="false"/>
-    <param name="rtp-timeout-sec" value="1800"/>
     <!--
 	DO NOT USE HOSTNAMES, ONLY IP ADDRESSES IN THESE SETTINGS!
     -->