Update bert
This pull request **introduces 2 alerts** when merging 786c4a83e0d6a48bf4732bb400e31c3b0b0dff21 into 6ce670b7ab3ab5c84ce388fa1968748cd859b8f8 - [view on LGTM.com](https://lgtm.com/projects/g/NVIDIA/NeMo/rev/pr-82f3d3ec49f1c660c34799fa45e15ff9271c68ef)

**new alerts:**

* 2 for Unused local variable