Authentik: change method to public and fix return (#1084)

Author: RixzZ

Provider.php

@@ -67,16 +67,18 @@ protected function getUserByToken($token)
     /**
      * {@inheritdoc}
      */
-    protected function refreshToken($refreshToken)
+    public function refreshToken($refreshToken)
     {
-        return $this->getHttpClient()->post($this->getTokenUrl(), [
+        $response = $this->getHttpClient()->post($this->getTokenUrl(), [
             RequestOptions::FORM_PARAMS => [
                 'client_id'     => $this->clientId,
                 'client_secret' => $this->clientSecret,
                 'grant_type'    => 'refresh_token',
                 'refresh_token' => $refreshToken,
             ],
         ]);
+
+        return json_decode((string) $response->getBody(), true);
     }
 
     /**