fix curl on php 7 (macOS 10.13)

#94

curl.php

@@ -72,8 +72,8 @@ public function execute()
                 }
                 $callback = $request->callback;
                 $callback($response);
-                curl_close($ch);
                 curl_multi_remove_handle(self::$multiHandle, $ch);
+                curl_close($ch);
             }
             if ($running || !$finish) {
                 if (curl_multi_select(self::$multiHandle, 1) === -1) {