No more no changes entries in the CHANGELOGs

During the `5.0.0.beta1` release, the CHANGELOGs got an entry like the
following:

```
* No changes.
```

It is kinda confusing as there are indeed changes after it. Not a
biggie, just a small pass over the CHANGELOGs.

[ci skip]

actioncable/CHANGELOG.md

 ## Rails 5.0.0.beta1 (December 18, 2015) ##
 
-*   No changes.
-
-
 *   Added to Rails!
 
-    *DHH*
\ No newline at end of file
+    *DHH*

actionmailer/CHANGELOG.md

 ## Rails 5.0.0.beta1 (December 18, 2015) ##
 
-*   No changes.
-
-
 *   `config.force_ssl = true` will set
     `config.action_mailer.default_url_options = { protocol: 'https' }`
 

actionpack/CHANGELOG.md

 ## Rails 5.0.0.beta1 (December 18, 2015) ##
 
-*   No changes.
-
-
 *   Deprecate `redirect_to :back` in favor of `redirect_back`, which accepts a
     required `fallback_location` argument, thus eliminating the possibility of a
     `RedirectBackError`.

actionview/CHANGELOG.md

 ## Rails 5.0.0.beta1 (December 18, 2015) ##
 
-*   No changes.
-
-
 *   `I18n.translate` helper will wrap the missing translation keys
      in a <span> tag only if `debug_missing_translation` configuration
      be true. Default value is `true`. For example in `application.rb`:

activejob/CHANGELOG.md

 ## Rails 5.0.0.beta1 (December 18, 2015) ##
 
-*   No changes.
-
-
 *   Fixed serializing `:at` option for `assert_enqueued_with`
     and `assert_performed_with`.
 

activemodel/CHANGELOG.md

 ## Rails 5.0.0.beta1 (December 18, 2015) ##
 
-*   No changes.
-
-
 *   Validate multiple contexts on `valid?` and `invalid?` at once.
 
     Example:

activerecord/CHANGELOG.md

@@ -4,9 +4,6 @@
 
 ## Rails 5.0.0.beta1 (December 18, 2015) ##
 
-*   No changes.
-
-
 *   Order the result of `find(ids)` to match the passed array, if the relation
     has no explicit order defined.
 

activesupport/CHANGELOG.md

 ## Rails 5.0.0.beta1 (December 18, 2015) ##
 
-*   No changes.
-
-
 *   Add thread_m/cattr_accessor/reader/writer suite of methods for declaring class and module variables that live per-thread.
     This makes it easy to declare per-thread globals that are encapsulated. Note: This is a sharp edge. A wild proliferation
     of globals is A Bad Thing. But like other sharp tools, when it's right, it's right.