With sig-keyserver-url $URL in gpg.conf:

$ gpg --pgp7 --detach-sign test

You need a passphrase to unlock the secret key for
[...]
gpg: can't put a preferred keyserver URL into v3 signatures

Now, I know that I can't do that but I don't want to be told about it
every time I sign something when I've explcitly enabled --pgp7. Would
it be unreasonable to ignore preferred keyserver urls when pgp[67] are
used?

I've been using the attached patch (minus the pgp2 part which I just
added) for a while to do just this and I haven't noticed any problems.
(There may be cleaner ways to do this, but this was what I got working
without knowing the code too well. :)

If it's not appropriate to patch this out, is there a good way to
silence this without losing other info? The --quiet option doesn't do
it.