[BUGFIX] AbstractBackendViewHelper uses namespaces

Namespaces are not supported in PHP 5.2.x, hence one must not
prefix a class name with backslash.

Regression fix to #54748.

Resolves: #59825
Releases: 4.5
Change-Id: Ideb2cef1c5e2ec0d2ac3328ebd4f318a161d368a
Reviewed-on: https://review.typo3.org/31084
Tested-by: Sebastian Sommer
Tested-by: Steffen Mächtel
Reviewed-by: Markus Klein
Tested-by: Markus Klein

typo3/sysext/fluid/Classes/ViewHelpers/Be/AbstractBackendViewHelper.php

@@ -43,7 +43,7 @@ abstract class Tx_Fluid_ViewHelpers_Be_AbstractBackendViewHelper extends Tx_Flui
 			$doc = t3lib_div::makeInstance('template');
 			$doc->backPath = $GLOBALS['BACK_PATH'];
 			if (!isset($GLOBALS['SOBE'])) {
-				$GLOBALS['SOBE'] = new \stdClass();
+				$GLOBALS['SOBE'] = new stdClass();
 			}
 			$GLOBALS['SOBE']->doc = $doc;
 		} else {