Currently, the flag is getting passed to gpgtar directly, which
doesn't know about the flag and exits. Instead, prepend a "--gpg-args"
to the parameter so that gpgtar passes it to gpg

T7320: Kleopatra: Decrypting and verifying a pgp-encrypted archive fails with "no data"

• Build gpgme with patch
• Try decrypting a gpg archive from kleopatra
• check that it works