Issue Summary

This is reproducible on Data Center: (yes)

Steps to Reproduce

1. Create an epic.
2. Create a Story. 
3. Link the Story to the Epic.
4. Go to the epic edit screen and add Story Points.
5. From the epic, go to the child issues, and add a negative value to the Story Point.

Expected Results

An error message preventing negative values:

Actual Results

The story point is updated with negative values

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available