reset cron interval to 15min

Signed-off-by: Artur Neumann <artur@jankaritech.com>

lib/BackgroundJob/CheckNotifications.php

@@ -47,7 +47,7 @@ public function __construct(ITimeFactory $time,
 								LoggerInterface $logger) {
 		parent::__construct($time);
 		// Every 15 minutes
-		$this->setInterval(15);
+		$this->setInterval(60 * 15);
 
 		$this->openprojectAPIService = $openprojectAPIService;
 		$this->logger = $logger;