Update git submodules
- Update extensions/CiteThisPage from branch 'REL1_39' to 9786d57e5b941e4e7e645cdf65bbd47c61f7ee75
- Localisation updates from https://translatewiki.net.
Change-Id: Ic3d0bbee5654ff5f22d48daaf940d3c8084a7c29
- Localisation updates from https://translatewiki.net.