make sure both channels are sip when dereferencing it's guts

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@8123 d0543943-73ff-0310-b7d9-9358b9ac24b2

src/mod/endpoints/mod_sofia/sofia.c

@@ -3077,7 +3077,7 @@ static void sofia_info_send_sipfrag(switch_core_session_t *aleg, switch_core_ses
 	private_object_t *b_tech_pvt = NULL, *a_tech_pvt = NULL;
 	char message[256] = "";
 
-	if (aleg && bleg) {
+	if (aleg && bleg && switch_core_session_compare(aleg, bleg)) {
 		a_tech_pvt = (private_object_t *) switch_core_session_get_private(aleg);
 		b_tech_pvt = (private_object_t *) switch_core_session_get_private(bleg);