Update git submodules
- Update skins/MonoBook from branch 'REL1_40' to 99067c8321a5f4f013cda9939b64628e66f8f125
- Localisation updates from https://translatewiki.net.
Change-Id: I3ba9a803fbb4b945b1ac7640588b8498a35ec889
- Localisation updates from https://translatewiki.net.