remove TaskRunner::isModern checks. leaving CreateWiki (waiting for email response) and PromoteImageReviewTask (another PR removes this)
remove TaskRunner::isModern() settings
removing legacy HAWelcomeJob
remove legacy job RefreshLinksJob
remove HTMLCacheUpdateJob
remove legacy ImageReviewTask
delete legacy job MultiDeleteTask
remove legacy task MultiMoveTask
remove legacy task MultiWikiEditTask
remove legacy job ReplaceTextJob
remove legacy UserRollbackTask
remove legacy tasks UserRenameGlobalTask and UserRenameLocalTask
Merge pull request #4433 from Wikia/jobq-isModernRemove

Jobqueue remove dead code