MAGETWO-71185: [Backport][2.1.x] - Braintree online refund not working for two websites using individual Braintree accounts

 - Fixed integration test

Author: YevSent

dev/tests/integration/testsuite/Magento/Braintree/Controller/Adminhtml/Payment/GetClientTokenTest.php

@@ -122,7 +122,7 @@ private function perform($merchantId, $publicKey, $privateKey)
         ];
 
         $adapter = $this->getMockBuilder(BraintreeAdapter::class)
-            ->setConstructorArgs($args)
+            ->setConstructorArgs(array_merge(['config' => null], $args))
             ->setMethods(['generate'])
             ->getMock();
         $adapter->method('generate')