Only use the NUMS_EX style if file is in skin
Only use the NUMS_EX style if file is in skin

Fixes a regression introduced when we changed the way skins are defined.

captbaritone/winamp2-js,YelaSeamless/winamp2-js,captbaritone/winamp2-js,captbaritone/winamp2-js,YelaSeamless/winamp2-js