modules: freetype: fix outline styles

My first patch to VLC fixing an issue where the outlines and shadows of subtitles would not be formatted with the same style as the actual glyph.

I believe the wrong style flags were given to vlc_ftcache_GetOutlinedGlyph: instead of passing it the style flags of the current run, we were giving it the style flags of the glyph from the font face. This would result in incorrect cache hits (or misses?).

Before:

After: