firefox: use sed instead of patch for freetype workaround

firefox/.md5sum

@@ -1,4 +1,3 @@
 d71f0f761c51aeae03e367001afc9f8d  firefox-41.0.2.source.tar.xz
 1c53b819f800c61cd50e7c47bdb30bf0  firefox-install-dir.patch
 cf6971669f70b440cb6ff8df8b2722ae  firefox.desktop
-efe2feea78bec0cf095ea9541ca5af78  freetype.patch

firefox/Pkgfile

@@ -7,12 +7,12 @@ name=firefox
 version=41.0.2
 release=2
 source=(http://ftp.mozilla.org/pub/firefox/releases/$version/source/firefox-$version.source.tar.xz
-	firefox-install-dir.patch firefox.desktop freetype.patch)
+	firefox-install-dir.patch firefox.desktop)
  
 build() {
     cd mozilla-release
 
-    patch -p1 -i $SRC/freetype.patch
+    sed -i '/^ftfntfmt.h/ i freetype/ftfntfmt.h' config/system-headers
     patch -p1 -i $SRC/firefox-install-dir.patch
  
 cat <<- EOF > .mozconfig

firefox/freetype.patch

@@ -1,12 +0,0 @@
-diff -rupN mozilla-release.orig/config/system-headers mozilla-release/config/system-headers
---- mozilla-release.orig/config/system-headers	2015-10-18 17:35:49.589375378 +0200
-+++ mozilla-release/config/system-headers	2015-10-18 17:36:45.288324530 +0200
-@@ -466,6 +466,7 @@ freetype/ftsizes.h
- freetype/ftadvanc.h
- freetype/ftbitmap.h
- freetype/ftxf86.h
-+freetype/ftfntfmt.h
- freetype.h
- ftcache.h
- ftfntfmt.h
-