Small improvement to drawin_geometry
Small improvement to drawin_geometry

Commit 487b8d6e5 made the argument to the geometry method of a drawin
optional, so that the geometry can be queried without setting it. This
was done by directly matching on the Lua value.

However, rlua implements FromLua for Option<T>, so instead of
implementing this optionality directly, Option can be used instead.

Signed-off-by: Uli Schlachter <346c0ad49ac8427b61b3b55abbe37dc0ebd524f2@znc.in>

Immington-Industries/way-cooler,way-cooler/way-cooler,Immington-Industries/way-cooler,way-cooler/way-cooler,Immington-Industries/way-cooler,way-cooler/way-cooler