Update git submodules
- Update extensions/VisualEditor from branch 'REL1_39' to bf604d8cfc49835cd8b83906cbcfb0e0f6ed1a9f
- Localisation updates from https://translatewiki.net.
Change-Id: Id3cd4dfb2ad1eb3d74173e99d052a517943a526e
- Localisation updates from https://translatewiki.net.