removed changes made during forward ports

Signed-off-by: Ashton Larkin <[email protected]>

Changelog.md

@@ -10,9 +10,6 @@
 1. Updated source build instructions for ign-gazebo4
     * [pull request 404](https://github.com/ignitionrobotics/ign-gazebo/pull/404)
 
-1. Revert diff_drive test changes from [pull request 314](https://github.com/ignitionrobotics/ign-gazebo/pull/314)
-    * [pull request 410](https://github.com/ignitionrobotics/ign-gazebo/pull/410)
-
 1. Add tests for the AnimationTime component
     * [pull request 433](https://github.com/ignitionrobotics/ign-gazebo/pull/433)
 
@@ -55,9 +52,6 @@
     * [pull request 452](https://github.com/ignitionrobotics/ign-gazebo/pull/452)
     * [pull request 469](https://github.com/ignitionrobotics/ign-gazebo/pull/469)
 
-1. Fixes for [pull request 463](https://github.com/ignitionrobotics/ign-gazebo/pull/463)
-    * [pull request 469](https://github.com/ignitionrobotics/ign-gazebo/pull/469)
-
 1. Use a [std::promise](https://en.cppreference.com/w/cpp/thread/promise)/[std::future](https://en.cppreference.com/w/cpp/thread/future) mechanism to avoid waiting in a looop until all `stepAck` messages are received
     * [pull request 470](https://github.com/ignitionrobotics/ign-gazebo/pull/470)