Burrito: kubernetes certificates are not renewed automatically

There is a regression bug in kubernetes certificate auto-renew script. The affected versions are from Burrito 1.2.4 to 2.1.2.

For users who are using those versions, follow the errata document at Errata.

Burrito 1.2.3 and earler does not have this bug and the latest version 2.1.3 has already this bug patched.