sanity-check-website failure email should include information about the detected errors
The current email reads:
sanity-check-website failed; for details, see https://staging.tails.boum.org/last-sanity-errors.txt
Experience shows that not including the details in the email decreases the chances that I look into it and fix the problem.
But including the details can occasionally lead to overly huge email, so what we do in at least another similar case is: if the details are small enough, include them in the email; else, point to where we can find them.
Parent Task: sysadmin#17274
- Related to #17650