sqv, gpgv: Do not fail if Dir::Etc::Trusted is set and trusted.gpg.d is missing
This should remain a warning case for now. So push the errors to a stack and see if we can find any file.
Explictly warn again if Dir::Etc::trusted is set, as it is like super deprecated.
Reported-By: Cyril Brulebois kibi@debian.org in Bug#1032131