When adding a Test Set to a Requirement, the rank of the Tests is not kept

Description

When adding a Test Set to a Requirement, the rank of the Tests is not kept.

How to reproduce

1. Create a Test Set and add Tests to it. Be sure they are not organized by issue key.
2. Add this Test Set to a Requirement

Actual result/Attachments

The Tests are automatically sorted by key desc.

Expected result

The order set in the Test Set should continue.