[ticket/12038] AJAXify move up/down buttons in the module management pages.

PHPBB3-12038

phpBB/includes/acp/acp_modules.php

@@ -170,6 +170,14 @@ class acp_modules
 					$this->remove_cache_file();
 				}
 
+				if ($request->is_ajax())
+				{
+					$json_response = new \phpbb\json_response;
+					$json_response->send(array(
+						'success'	=> ($move_module_name !== false),
+					));
+				}
+
 			break;
 
 			case 'quickadd':