Removing Policy URLs

[Khelben Blackstaff]

Greetings.

I would like to know how can i remove a policy url from a (sub)key
(it isn't stored on a key server). There is probably a very easy way
to do it but i could not find it in the manpage or the mailing list
archive.

I use set-policy-url in gpg.conf and it works fine but i forgot it
when i generated a new authentication key and it got the policy url.
I tried "set-policy-url none" together with a expire date change so that
the signature is modified but the policy wasn't touched. I tried
"key 3" and delsig but delsig needs a uid and not a subkey.

How can i delete the policy url (or the whole signature and recreate it)
from a subkey ?

Thank you for your time.