add redirection to /administrator/

[semik]

I find it confusing that when you type https://czertainly.domain/ you get an error saying just:

Error

no Route matched with those values.

This simple patch makes use of an nginx ingress configuration snippet to redirect the user to the right place https://czertainly.domain/administrator/ The reason why it is by default disabled is that snippet-annotations are also by default disabled in nginx ingress. According to docs they might introduce security risk on the cluster.

[semik]

Looks like it affects certificate passing...