Improve error message when package is missing required signature

When attempting to install a package (either via -S or -U) and the
signature is missing, the current error message "invalid or corrupted
package (PGP signature)" is very unclear.  Instead inform the user
that the package is missing the required signature.

Partial fix for FS#34741.

Signed-off-by: Allan McRae <allan@archlinux.org>

0 files changed, 0 insertions, 0 deletions