remove double checked retrans

kamailio/default.cfg

@@ -531,9 +531,6 @@ route[PREPARE_INITIAL_REQUESTS]
         exit();
     }
 
-    # handle re-transmissions
-    t_check_trans();
-
     if (is_method("UPDATE")) {
         xlog("L_WARN", "$ci|end|update outside dialog not allowed");
         send_reply("403", "Dialog does not exist");