Update author name

Author: mustafauysal

plugin.php

@@ -6,7 +6,7 @@
  * Version:           1.0
  * Requires at least: 5.7
  * Requires PHP:      7.2.5
- * Author:            PoweredCache
+ * Author:            Powered Cache
  * Author URI:        https://poweredcache.com/
  * License:           GPL v2 or later
  * License URI:       https://www.gnu.org/licenses/gpl-2.0.html