Update git submodules
- Update extensions/Gadgets from branch 'REL1_39' to 0143be9d27f80542f56c39bd0a718d712aadc856
- Localisation updates from https://translatewiki.net.
Change-Id: Ic11c93bcfbae58b63c21d1c37771c3186191af22
- Localisation updates from https://translatewiki.net.