add 100ms usleep to reduce request frequency

switchepp.php

@@ -1017,7 +1017,7 @@ function switchepp_Sync($params)
      * [error] => Command failed; server closing connection. Too many requests per second! Timeout ms.: 47107
      * using usleep to slow down request frequency
     */
-    usleep(100000);
+    usleep(500000);
     try {
         $client = switchepp_clientloginepp($params);      #Epp Connection
         $login = switchepp_loggedinepp($client, $params);      #Epp Client login