Fix progress button functionality on dashboard page.
Fix progress button functionality on dashboard page.

The progress dialog has click handlers on each of its avatar images.
These used css selector .avatar-image but there are also avatar
images on the main rows of the dashboard itself. Furthermore, there
is a heartbeat which auto refreshes and each refresh was adding a new
click handler to all .avatar-image selections, including (incorrectly)
the ones on the progress dialog. So refine the css selector on the
heartbeat.

cyber-dojo/web,cyber-dojo/web,cyber-dojo/web,cyber-dojo/web