Update git submodules
- Update extensions/VisualEditor from branch 'REL1_39' to 7c2526462bc046db49b1dd90b1f69b762ced5d1d
- Localisation updates from https://translatewiki.net.
Change-Id: I67a0a8ecfc5e03359d08516dba9ed5043a9fc8ad
- Localisation updates from https://translatewiki.net.