Patch DB mezi 2.0 -> 2.1 opravujici 'on update CURRENT_TIMESTAMP'

src/warden-server/doc/warden20to21.patch

+ALTER TABLE  `clients` CHANGE  `registered`  `registered` TIMESTAMP NOT NULL DEFAULT  '0000-00-00 00:00:00';
+ALTER TABLE  `events` CHANGE  `detected`  `detected` TIMESTAMP NOT NULL DEFAULT  '0000-00-00 00:00:00';