only load apps if they exist

lib/app.php

@@ -60,9 +60,11 @@ class OC_APP{
 		$apps = OC_APPCONFIG::getApps();
 		foreach( $apps as $app ){
 			if( self::isEnabled( $app )){
+				if(is_file($SERVERROOT."/apps/$app/appinfo/app.php")){
 					require( "apps/$app/appinfo/app.php" );
 				}
 			}
+		}
 
 		self::$init = true;