[GTK] Bump fontconfig version to 2.12.4

[GTK] Bump fontconfig version to 2.12.4
https://bugs.webkit.org/show_bug.cgi?id=176997

Reviewed by Michael Catanzaro.

It's the latest stable version and we can get rid of the patches we have.

* WebKitTestRunner/gtk/fonts/fonts.conf: Remove hinting config we no longer need with newer FreeType and
deprecated <blank> that current fontconfig just ignores.
* gtk/jhbuild.modules:
* gtk/patches/fontconfig-2.11.1-add-autogen.patch: Removed.
* gtk/patches/fontconfig-Avoid-conflicts-with-integer-width-macros-from-TS-18661-1-2014.patch: Removed.
* gtk/patches/fontconfig-Fix-the-build-issue-with-gperf-3.1.patch: Removed.
* gtk/patches/fontconfig-fix-osx-cache.diff: Removed.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@222128 268f45cc-cd09-0410-ab3c-d52691b4dbfc