Add patch to replace gpgme with gpg + update Suggests

Closes: #876983

Now the tool does not crash when a GPG signature is detected:

bmaptool: info: discovered bmap file 'empty.bin.bmap'
bmaptool: info: discovered signature file for bmap 'empty.bin.bmap.asc'
bmaptool: WARNING: the "empty.bin.bmap.asc" signature file does not actually contain any valid signatures
bmaptool: info: block map format version 2.0

However I still need to figure out why the signature file is said to not contain any signature (both with gpg --sign and gpg --clearsign).