Update git submodules
- Update extensions/CategoryTree from branch 'REL1_39' to 6347ab8de152509529ec2e3ead50318ae7e8e07a
- Localisation updates from https://translatewiki.net.
Change-Id: I17517a7e53fa226d39733230c52970e8e8f4cd7f
- Localisation updates from https://translatewiki.net.