Fix typo in changelog link ref [ci skip]

Author: bf4

CHANGELOG.md

@@ -415,7 +415,7 @@ Features:
     '[Revert the serializers API as other alternatives are now also under discussion](https://github.com/rails/rails/commit/0a4035b12a6c59253cb60f9e3456513c6a6a9d33)'.
 - [Proposed Implementation to Rails 3.2 by @wycats and @josevalim (November 25, 2011)](https://github.com/rails/rails/pull/3753)
   - [Creation of `ActionController::Serialization`, initial serializer
-    support (September, 26 2011)](https://github.com/rails/rails/commit/8ff7693a8dc61f43fc4eaf72ed24d3b8699191fe0).
+    support (September, 26 2011)](https://github.com/rails/rails/commit/8ff7693a8dc61f43fc4eaf72ed24d3b8699191fe).
   - [Docs and CHANGELOG](https://github.com/rails/rails/commit/696d01f7f4a8ed787924a41cce6df836cd73c46f)
   - [Deprecation of ActiveModel::Serialization to ActiveModel::Serializable](https://github.com/rails/rails/blob/696d01f7f4a8ed787924a41cce6df836cd73c46f/activemodel/lib/active_model/serialization.rb)
 - [Creation of `ActiveModel::Serialization` from `ActiveModel::Serializer` in Rails (2009)](https://github.com/rails/rails/commit/c6bc8e662614be711f45a8d4b231d5f993b024a7#diff-d029b9768d8df0407a35804a468e3ae5)