Burndown chart counts down from 0.

Summary

The burndown chart starts at 0 even with open issues and then counts down.

Steps to reproduce

Not sure, I created a milestone and added issues to it.

Example Project

%v0.1 in codeshelter/codeshelter-web

What is the current bug behavior?

The chart counts down from 0.

What is the expected correct behavior?

It should count down from 5.