media-gfx/openscad: fix automagic deps

media-gfx/openscad: fix automagic deps

Fixes issues with automagic dependencies in upstream build system,
where it links against dev-libs/libspnav and dev-libs/hidapi if
they are present on the build host.

Thanks to Phil Stracchino (Unix Ronin) for bringing this up.

Closes: https://bugs.gentoo.org/686354
Reported-by: Phil Stracchino (Unix Ronin) <phils@caerllewys.net>
Package-Manager: Portage-2.3.62, Repoman-2.3.12
Signed-off-by: Bernd Waibel <waebbl@gmail.com>
Signed-off-by: Michał Górny <mgorny@gentoo.org>