gverify: Remove gpg import with --recv-keys

[AbcSxyZ]

Suggesting removing import of gpg key during gverify which use --recv-keys.

Look like it's trying to retrieve a key using a signature.pgp file. The current command will fail if this file is not provided, with the command/line becoming useless.

You do not give any explanation about this file, documentation of gverify ask to import public key before running the command. I'm suspecting a deprecated feature, and I may be wrong but it doesn't seem to be generated by the program.