Update git submodules
- Update extensions/VisualEditor from branch 'REL1_39' to a86a0024666bfbcfc0069c6e8b48616a2241f311
- Localisation updates from https://translatewiki.net.
Change-Id: I49942f26d1208e41752922517e187d28734c971d
- Localisation updates from https://translatewiki.net.