Merge pull request #54944 from nextcloud/backport/54941/stable31

[stable31] fix(cache): Set default Redis port to `0` for UNIX sockets

Author: AndyScherzinger

lib/private/RedisFactory.php

@@ -77,7 +77,7 @@ private function create() {
 			$this->instance = new \Redis();
 
 			$host = $config['host'] ?? '127.0.0.1';
-			$port = $config['port'] ?? ($host[0] !== '/' ? 6379 : null);
+			$port = $config['port'] ?? ($host[0] !== '/' ? 6379 : 0);
 
 			$this->eventLogger->start('connect:redis', 'Connect to redis and send AUTH, SELECT');
 			// Support for older phpredis versions not supporting connectionParameters