gpgconf: Return a new pseudo option compliance_de_vs.

* tools/gpgconf-comp.c (known_pseudo_options_gpg): Add
"compliance_de_vs".
* g10/gpg.c (gpgconf_list): Returh that pseudo option.

Of course this will always return false for this version of gnupg.
But as soon as this version has been approved we have everything ready
for a runtime check.

• Signed-off-by: Werner Koch <wk@gnupg.org>