Handle empty 204 Requests returned by CCP's PUT and DELETE methods

[PeterDKC]

ESI returns HTTP 204 responses for PUT and DELETE operations.

There's a deficiency in the base oauth2 library that sends empty response bodies to json_decode(), which then throws an UnexpectedValueException even though the request has succeeded and returned a 2xx ( 204 in this case ) response status code.

This workaround solves the issue:

+        if (empty($content) && $response->getStatusCode() === 204) {
+            return $content;
+        }