MQE-1181: Fatal error while test running

- Added null check for getDriver

Author: aljcalandra

src/Magento/FunctionalTestingFramework/Extension/PageReadinessExtension.php

@@ -187,7 +187,11 @@ function () use ($metrics) {
     private function checkForNewPage($step)
     {
         try {
-            $currentUri = $this->getDriver()->_getCurrentUri();
+            if (isset($this->getDriver())) {
+                $currentUri = $this->getDriver()->_getCurrentUri();
+            } else {
+                throw new \Exception();
+            }
 
             if ($this->uri !== $currentUri) {
                 $this->logDebug(