Created attachment 916322 [details]
[test run] If test run already added all Environment property values for one property, edit one of the values in run detail page, system will load null for value options.

Description of problem:
as summary.

Version-Release number of selected component (if applicable):
v3.8.9-1 on test server.

How reproducible:
100%

Steps to Reproduce:
1.Enter a test run detail page.
https://tcms-test.app.eng.nay.redhat.com/run/155001/
2.click Add Property link in Environment form, then add all values(8 values) for Property 'smp'.
3.In run detail page, choose one of the Environment Property, click edit btn after the Property, inspect the values system load. 

Actual results:
system load null for Environment Property.

Expected results:
system load the current value for Environment Property.

Additional info: