BugLink: https://bugs.launchpad.net/bugs/1861284

When the build of wireguard modules is disabled, its modules should be
ignored, just like when zfs is disabled.
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com
Signed-off-by: Ian May <ian.may@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>