Update CHANGELOG.md

Author: SkafteNicki

CHANGELOG.md

@@ -38,9 +38,6 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 - Expose DeepSpeed loss parameters to allow users to fix loss instability ([#6115](https://github.com/PyTorchLightning/pytorch-lightning/pull/6115))
 
 
-- Expose DeepSpeed loss parameters to allow users to fix loss instability ([#6115](https://github.com/PyTorchLightning/pytorch-lightning/pull/6115))
-
-
 - Fixed epoch level schedulers not being called when `val_check_interval < 1.0` ([#6075](https://github.com/PyTorchLightning/pytorch-lightning/pull/6075))