Add extra check so we don't error out on type

json_decode can return false if we have invalid data.
In that case just assume there was nothing cached

Signed-off-by: Roeland Jago Douma <roeland@famdouma.nl>

lib/private/OCS/DiscoveryService.php

@@ -65,7 +65,10 @@ class DiscoveryService implements IDiscoveryService {
 		// Check the cache first
 		$cacheData = $this->cache->get($remote . '#' . $service);
 		if($cacheData) {
-			return json_decode($cacheData, true);
+			$data = json_decode($cacheData, true);
+			if (\is_array($data)) {
+				return $data;
+			}
 		}
 
 		$discoveredServices = [];