Revert the following change, because Memcached is not present
in MariaDB Server. We had better avoid adding dead code.

commit d9bc5e03d788b958ce8c76e157239953db60adb2
Author: Aakanksha Verma <aakanksha.verma@oracle.com>
Date:   Thu May 18 14:31:01 2017 +0530

    Bug #24605783 MYSQL GOT SIGNAL 6 ASSERTION FAILURE