Translated taint message.
Also added a blank line before "Current system is tagged" for better
visual separation between current system state and tags description.
Let's allow distros to change the support URL to expose in catalog entries by
default. It doesn't make sense to direct end-users to the upstream project for
common errors.
This adds a --with-support-url= switch to configure, which allows overriding
the default at build-time.
Fixes: #2516