Move all references of old url to the new address (#622)

diff --git a/src/hb-private.hh b/src/hb-private.hh
index b6d13bd..9c55b4b 100644
--- a/src/hb-private.hh
+++ b/src/hb-private.hh
@@ -692,7 +692,7 @@
  * one enum to another...  So this doesn't provide the type-checking that I
  * originally had in mind... :(.
  *
- * For MSVC warnings, see: https://github.com/behdad/harfbuzz/pull/163
+ * For MSVC warnings, see: https://github.com/harfbuzz/harfbuzz/pull/163
  */
 #ifdef _MSC_VER
 # pragma warning(disable:4200)