Updated mediawiki/extensions
Project: mediawiki/extensions/Parsoid  52356b6844949862680e537e942ab0fd61d73e2c

Revise comparison FIXME with a more precise description and assertion.

This bug was fixed in https://gerrit.wikimedia.org/r/59440 but keep the
assertion here to prevent a future regression.

Change-Id: Ia3b68e7b2077e426e2b6543744ffdb8c34083551