[BUGFIX] Possible silent fatal error with legacy extensions

The use of the '@' symbol while including an extension update script
may result into a PHP fatal error being totally muted which in turn
results into a blank screen.

This happens when a legacy extension is extending t3lib_SCbase in its
update script and EXT:compatibility6 is not loaded.

Having a white screen and no log entry makes it really hard to
understand where the error comes from. The Install Tool does not help
either since the check for broken extensions only tries to include
ext_tables.php and ext_localconf.php.

Change-Id: I9078882e10739309ac160f4ac5a0dfcfd49fbba1
Resolves: #70697
Releases: master
Reviewed-on: http://review.typo3.org/44059


Reviewed-by: Mathias Schreiber <mathias.schreiber@wmdb.de>
Tested-by: Mathias Schreiber <mathias.schreiber@wmdb.de>
Reviewed-by: Alexander Opitz <opitz.alexander@googlemail.com>
Tested-by: Alexander Opitz <opitz.alexander@googlemail.com>

typo3/sysext/extensionmanager/Classes/Utility/UpdateScriptUtility.php

@@ -117,7 +117,7 @@ class UpdateScriptUtility
         } else {
             $className = $matches[1] . '\ext_update';
         }
-        @include_once $updateScript;
+        include_once $updateScript;
         if (!class_exists($className, false)) {
             throw new ExtensionManagerException(
                 sprintf('class.ext_update.php of extension "%s" did not declare ext_update class', $extensionKey),