lua: update Libs in lua.pc

Update Libs in lua.pc so that pkg-config --libs gives the correct list
of libraries for linking. This makes us effectively list the same
libraries as Fedora does.

Signed-off-by: Maciej Borzecki <maciej.borzecki@open-rnd.pl>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>