Commit https://github.com/jenkinsci/jenkins/commit/a97c9188dfacec2f251f1fc6545d1104a33d0b15 broke the ability to "tail" the console output for an active job. Before this, scrolling down to the bottom of the console log stayed at the bottom as more material was posted to the log. Now, the console stays at the same place in the log (and a user has to keep scrolling / pressing "End" or "Page Down" to see new material).

Reverting this commit restores functionality for the master branch.