Updated mediawiki/extensions
Project: mediawiki/extensions/VisualEditor  fdf40f1655b9d34750a47cf095295490c3af3cb6

Convert MWBlockImage dimensions to numbers and update tests

MWInlineImage already does this but it wasn't copied over to
MWBlockImage.

Change-Id: I9f34182b30ae72beb7b5c3d5fde2f08185cba663