[BUGFIX] Do not use $_EXTKEY

Author: benjaminkott

ext_localconf.php

@@ -12,7 +12,9 @@
 /***************
  * PageTS
  */
-\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addPageTSConfig('<INCLUDE_TYPOSCRIPT: source="FILE:EXT:' . $_EXTKEY . '/Configuration/TsConfig/Page/All.tsconfig">');
+\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addPageTSConfig(
+    '<INCLUDE_TYPOSCRIPT: source="FILE:EXT:syntax/Configuration/TsConfig/Page/All.tsconfig">'
+);
 
 /***************
  * Register Icon