Pushed to branch ikloecker/t5462 for easier integration as rG0a7d772a5c43: gpgconf: Allow changing gpg's deprecated keyserver option.

Having it invisible is okay for me. But we should not support the keyserver option in gpg.conf via Kleopatra anymore. This option needs to be faded out. Actually there are more problems in 2.2 here: In particular the global options are not manageable by a gpgconf. Thus there is no guarantee that the keyserver option actually shows the correct value if global options are used.

In D538#5324, @werner wrote:

Having it invisible is okay for me. But we should not support the keyserver option in gpg.conf via Kleopatra anymore. This option needs to be faded out.

And it will be faded out. Kleopatra does not set/change this option unless it is already set, i.e. it's only used for old installations. If the user sets the keyserver for the first time, then Kleopatra will set dirmngr's keyserver option. See also T5677 which will make sure that "invisible" options are no longer offered in Kleopatra's UI.

In D538#5324, @werner wrote:

Actually there are more problems in 2.2 here: In particular the global options are not manageable by a gpgconf. Thus there is no guarantee that the keyserver option actually shows the correct value if global options are used.

gpgme supports read-only options and Kleopatra tries to disable editing of read-only options. So it's just a matter of making sure that gpgconf --list-options reports the values of global options and flags them as read-only.