Merge pull request #24765 from owncloud/boolean-installed-config

 	Make sure we evaluate installed everywhere as a boolean

lib/private/Updater.php

@@ -168,6 +168,7 @@ class Updater extends BasicEmitter {
 
 		$this->emit('\OC\Updater', 'resetLogLevel', [ $logLevel, $this->logLevelNames[$logLevel] ]);
 		$this->config->setSystemValue('loglevel', $logLevel);
+		$this->config->setSystemValue('installed', true);
 
 		return $success;
 	}

status.php

@@ -31,8 +31,8 @@ try {
 
 	$systemConfig = \OC::$server->getSystemConfig();
 
-	$installed = $systemConfig->getValue('installed') == 1;
-	$maintenance = $systemConfig->getValue('maintenance', false);
+	$installed = (bool) $systemConfig->getValue('installed', false);
+	$maintenance = (bool) $systemConfig->getValue('maintenance', false);
 	$values=array(
 		'installed'=>$installed,
 		'maintenance' => $maintenance,