Description of problem:

TCMS TestRun update does not update / refresh all case runs (as expected):

Let's have following scenario:
Test plan (6518) created with couple of test cases.
I created test runs for that plan (42191-4).
In the meantime some test case descriptions changed so I used test run update functionality to update caseruns to latest test case revisions.

This function succeeded but did not update all case runs as expected.

For instance:
  https://tcms.engineering.redhat.com/run/42191/
contains caserun 1284695 which still refers to test case 175957 revision 1 (rev 2 is last one existing).

Re-running test-run 42191 update does nothing.


Version-Release number of selected component (if applicable):
Nitrate 3.7.1

How reproducible:
100%

Steps to Reproduce:
1. Update https://tcms.engineering.redhat.com/run/42191/
   Showing 0 updates.
2. Check that caserun 1284695 still shows test case 175957 rev 1 instead of rev 2
3. Doublecheck that case 175957 contain two revisions:
   https://tcms.engineering.redhat.com/case/175957/history/?from_plan=
  
Actual results:
  Test run update does not perform all caserun updates.

Expected results:
  Test run update should perform all caserun updates.

Additional info:

  Workaround is to create new set of runs and transfer all info including from old test runs.