Add timeout for requests to appstore

Signed-off-by: Morris Jobke <hey@morrisjobke.de>

lib/private/App/AppStore/Fetcher/Fetcher.php

@@ -78,7 +78,9 @@ abstract class Fetcher {
 			return [];
 		}
 
-		$options = [];
+		$options = [
+			'timeout' => 10,
+		];
 
 		if ($ETag !== '') {
 			$options['headers'] = [