fix set view in help to null

Author: matbech

test/Helper/HeadScriptTest.php

@@ -446,15 +446,14 @@ public function testNoEscapeWithAllowArbitraryAttributesDoesNotIncludeNoEscapeSc
     public function testNoEscapeDefaultsToFalse()
     {
         // it only defaults to false if there is no view, respectively no doctype helper available
-        $oldview = $this->view;
-        $this->view = null;
+        $this->helper->setView(null);
         $this->helper->__invoke()->appendScript('// some script' . PHP_EOL, 'text/javascript', []);
         $test = $this->helper->__invoke()->toString();
 
         $this->assertContains('//<!--', $test);
         $this->assertContains('//-->', $test);
 
-        $this->view = $oldview;
+        $this->helper->setView($this->view);
     }
 
     public function testNoEscapeTrue()