GRAL-2200: fix content-type

Author: ziimk

src/Controllers/DealsController.php

@@ -571,7 +571,7 @@ public function updateADeal(
         //prepare headers
         $_headers = array (
             'user-agent'    => BaseController::USER_AGENT,
-            'Accept'        => 'application/json',
+            'content-type'  => 'application/json; charset=utf-8',
             'Authorization' => sprintf('Bearer %1$s', Configuration::$oAuthToken->accessToken)
         );
 

src/Controllers/OrganizationsController.php

@@ -434,7 +434,7 @@ public function updateAnOrganization(
         //prepare headers
         $_headers = array (
             'user-agent'    => BaseController::USER_AGENT,
-            'Accept'        => 'application/json',
+            'content-type'  => 'application/json; charset=utf-8',
             'Authorization' => sprintf('Bearer %1$s', Configuration::$oAuthToken->accessToken)
         );