Fixed ta_start/end bug in nta. Patch by Colin Whittaker.

darcs-hash:20060601105211-7659e-f7c868efb374817fc2de3bd0503633c09890973b.gz

libsofia-sip-ua/nta/nta.c

@@ -2775,6 +2775,8 @@ int nta_msg_mreply(nta_agent_t *agent,
   msg_destroy(reply);
   msg_destroy(req_msg);
 
+  ta_end(ta);
+
   return retval;
 }