Updated mediawiki/extensions
Project: mediawiki/extensions/Scribunto  ad3e5a7c4879772f75f7f75bc249a296f86ed545

Fix LuaSandbox mw.ustring.byteoffset with negative 'i'

Negative values for 'i' in mw.ustring.byteoffset are supposed to count
from the end of the string. But in LuaSandbox, it was actually counting
from two bytes before the end of the string due to a typo.

Fix that, and add some tests for it.

Bug: 50176
Change-Id: Iceee1022a55abd7a08df1ea7843e1277eb02798b