[BUGFIX] PHP fatal error calling beuser module

A missing namespace import triggers a PHP fatal error
in ext:beuser.

Resolves: #64893
Related: #64695
Releases: master
Change-Id: I366203ad87aa5823fcf9099525bf99ea003a9533
Reviewed-on: http://review.typo3.org/36695


Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Nicole Cordes <typo3@cordes.co>
Tested-by: Nicole Cordes <typo3@cordes.co>

typo3/sysext/beuser/Classes/ViewHelpers/IssueCommandViewHelper.php

@@ -14,6 +14,8 @@ namespace TYPO3\CMS\Beuser\ViewHelpers;
  * The TYPO3 project - inspiring people to share!
  */
 
+use TYPO3\CMS\Backend\Utility\BackendUtility;
+
 /**
  * Issue command ViewHelper, see TYPO3 Core Engine method issueCommand
  *