Remove all TTF font files

The TTF files are not served or used for anything else than converting
them to woff and woff2 formats, so there is no need to store them in the
git repo. In case a new format comes along, we would need to fetch these
from the git history or from upstream sources.

Change-Id: Iedc9162011b3b37587a2a176949afde6878d122d

data/fontrepo/fonts/GentiumPlus/font.ini

@@ -4,7 +4,6 @@ version=6.001
 license=OFL-1.1
 licensefile=OFL.txt
 url=http://scripts.sil.org/gentium
-ttf=GentiumPlus-Regular.ttf
 woff=GentiumPlus-Regular.woff
 woff2=GentiumPlus-Regular.woff2
 italic=GentiumPlus Italic
@@ -12,19 +11,16 @@ bold=GentiumPlus Bold
 bolditalic=GentiumPlus Bold Italic
 
 [GentiumPlus Bold]
-ttf=GentiumPlus-Bold.ttf
 woff=GentiumPlus-Bold.woff
 woff2=GentiumPlus-Bold.woff2
 fontweight=bold
 
 [GentiumPlus Italic]
-ttf=GentiumPlus-Italic.ttf
 woff=GentiumPlus-Italic.woff
 woff2=GentiumPlus-Italic.woff2
 fontstyle=italic
 
 [GentiumPlus Bold Italic]
-ttf=GentiumPlus-BoldItalic.ttf
 woff=GentiumPlus-BoldItalic.woff
 woff2=GentiumPlus-BoldItalic.woff2
 fontstyle=italic