Workaround for linking failure

Avoiding use of system openjpeg libraries temporarily solves final
linking failure.

PKGBUILD

@@ -128,6 +128,7 @@ build() {
   cp "$_ungoogled_repo/flags.gn" "out/Default/args.gn"
   printf '\n' >> "out/Default/args.gn"
   cat "$_ungoogled_archlinux_repo/flags.archlinux.gn" >> "out/Default/args.gn"
+  sed -i '/use_system_libopenjpeg2=true/d' "out/Default/args.gn"
 
   # Facilitate deterministic builds (taken from build/config/compiler/BUILD.gn)
   CFLAGS+='   -Wno-builtin-macro-redefined'