The content hash of each RPM is already verified, so verifying
signatures again is not necessary if the manifest generation is trusted,
and verifying signatures does not help if the manifest generation is
not.
Let us follow what DNF does and default to not verify signatures, but in
order to preserve features already in use we still allow opting in to
verifying signatures as before on a per RPM basis.
This will make it possible to install unsigned RPMs, or a mixed of
signed and unsigned RPMs.
Signed-off-by: Tom Gundersen <teg@jklm.no>
fca588d4b5