Update VE core submodule to master (50be82b)

New changes:
11cc189 Localisation updates from https://translatewiki.net.
51a7ebe Followup de40432: fix JS errors in Firefox
90706af Fix conversion of non-paragraph content-containing nodes in sanitize
50be82b Localisation updates from https://translatewiki.net.

Change-Id: Id59e7b235937c2b97ecb7cb876f433f0a634045c