Merge pull request #15194 from owncloud/fix-15146

Do not use APCu when apc.enabled is Off.

lib/private/memcache/apcu.php

@@ -12,6 +12,8 @@ class APCu extends APC {
 	static public function isAvailable() {
 		if (!extension_loaded('apcu')) {
 			return false;
+		} elseif (!ini_get('apc.enabled')) {
+			return false;
 		} elseif (!ini_get('apc.enable_cli') && \OC::$CLI) {
 			return false;
 		} elseif (version_compare(phpversion('apc'), '4.0.6') === -1) {