Patch version.gni for Fuchsia

This should be fixed in Chromium's ICU as well.

Change-Id: Ibd31e145b415d969dd45f2830b0fc851cb33c9af
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/icu/+/449858
Reviewed-by: Fabrice de Gans-Riberi <fdegans@google.com>

version.gni

diff --git a/version.gni b/version.gni
index 9e1881f..169e550 100644
--- a/version.gni
+++ b/version.gni
@@ -6,5 +6,5 @@
   # Contains the major version number of the ICU library, for dependencies that
   # need different configuration based on the library version. Currently this
   # is only useful in Fuchsia.
-  icu_major_version_number = "67"
+  icu_major_version_number = "68"
 }