Updated mediawiki/extensions
Project: mediawiki/extensions/Parsoid  51d49eb7584a57c459d6409545e299ce61a3c34a

[Bug 55902]: <BR> special case in makeSeparator

* Fixes one selser test and should eliminate noisy, but spurious,
  regression in rt testing.

Change-Id: I20683153e7ec445b3a370e13c5c9a25c15357327