Update git submodules
- Update extensions/WikiEditor from branch 'REL1_39' to d706de2f7f5a256b5815b2304004f5205ff08105
- Localisation updates from https://translatewiki.net.
Change-Id: I3cab6de00a6b43c9e66994416606dad387eb8827
- Localisation updates from https://translatewiki.net.