Updated mediawiki/extensions
Project: mediawiki/extensions/Echo  17b648f18f608b8cdf70d640b603744ec22e0ba8

Remove dead code

While writing tests i noticed that this is dead code that will never be called. It
was originally used but several commits have piled up to cause its deprecation.
Upon review of the git history it seems the general idea behind content-* turned
into the 'payload' key. the commentText formatting was moved to payload for future
use, the i18n keys have been pruned.

Change-Id: I5ef360759db53d54a834afc8b71e9c8807de0284