fix error where api identifiers were lingering between calls

Author: alastair.mayer

php-client/class.phpipam-api.php

@@ -538,6 +538,7 @@ public function set_api_controller ($controller = false) {
      * @return void
      */
     public function set_api_identifiers ($identifiers) {
+        $this->api_server_identifiers = false;         // clear this to forget any previous settings 
         if(is_array($identifiers)) {
             if(sizeof($identifiers)>0 && !$this->api_encrypt) {
                 // reset