Revert "contribs: disable harfbuzz for WinRT"

This reverts commit 2f33ac5b.
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

contrib/src/ass/rules.mak

@@ -24,7 +24,7 @@ WITH_HARFBUZZ = 1
 else
 ifdef HAVE_WINRT
 WITH_FONTCONFIG = 0
-WITH_HARFBUZZ = 0
+WITH_HARFBUZZ = 1
 else
 WITH_FONTCONFIG = 1
 WITH_HARFBUZZ = 1