A few years ago, libfreetype introduced FT_Get_Font_Format() as an alias for
FT_Get_X11_Font_Format(), but FT_Get_X11_Font_Format() was kept for abi
backwards-compatibility.
Our qt bump to 5.9 introduced a call to FT_Get_Font_Format(). Replace it with
FT_Get_X11_Font_Format() in order to remain compatibile with older freetype,
which is still used by e.g. Ubuntu Trusty.
Github-Pull: #14348
Rebased-From: 430bf6c7a1
Tree-SHA512: fd22b824e7251a7975d9e9222eff06d2b04ebf30e13aeccab580596c042b3abe2f62da1f0ef75106b0b171368ee1062ef2f459cfa435aa54826766a9005b80df