Add i18n globals to PHP entry point

Even though the PHP entry point is deprecated, some part of its
structure is still required for the mergeMessageFileList.php maintenance
script. Ensure that this structure is present here.

Author: lucaswerkmeister

WikibaseImport.php

@@ -2,6 +2,9 @@
 
 if ( function_exists( 'wfLoadExtension' ) ) {
 	wfLoadExtension( 'WikibaseImport', __DIR__ . '/extension.json' );
+	// Keep i18n globals so mergeMessageFileList.php doesn't break
+	$wgMessagesDirs['WikibaseImport'] = __DIR__ . '/i18n';
+	$wgExtensionMessagesFiles['WikibaseImportAlias'] = __DIR__ . '/WikibaseImport.i18n.alias.php';
 	wfWarn(
 		'Deprecated PHP entry point used for WikibaseImport extension. ' .
 		'Please use wfLoadExtension instead, ' .