Update git submodules
- Update extensions/WikiEditor from branch 'REL1_39' to c8a230cab71721fe8b9ff6d6b3e260afe6da5a3f
- Localisation updates from https://translatewiki.net.
Change-Id: I2f79189048ee8e79704270152dce69573058eb1d
- Localisation updates from https://translatewiki.net.