Remove message about ignored certificates without user IDs

This information doesn't really help the users because there's nothing
they can do about it (maybe unless its their own certificate). This
happens with OpenPGP keyservers that nowadays enforce the validation of
email addresses before they publish them.

(cherry picked from commit cdf162baa1eef9b17b6cadd37329029c3cb4b3aa)

• GnuPG-bug-id: T6493