Update VE core submodule to master (07923f7)

New changes:
05f775d Update OOjs UI to v0.1.0-pre (46ccd5b3a7)
2fc4673 Localisation updates from https://translatewiki.net.
07923f7 Update OOjs UI to v0.1.0-pre (ac0cc69508)

Change-Id: I7a959bc500a7dbf69305985de43b7814cd010838