Burndown chart is off

Created by: eseliger

• Sourcegraph version: master
• Platform information: macOS 10.15.4, Chrome 81

Steps to reproduce:

1. Sadly don't really know. I have a campaign with quite a few published changesets.

Expected behavior:

The count of changesets is equal to the count of changesets shown in the burndown chart.

Actual behavior:

It almost feels like 50 is a query limit interally?