We had the same situation earlier, when we contacted Qlik Official support they said, as per agreement (between Qlik and X company) you are not supposed to use the same license in two places,Get a license for test server separately.
This may differ based on your company initial agreements with the Qlik.
Qlik may have some different agreements depending on the customers and geography.
Please check with your Official Qlik contact regarding this. That will be the final answer for your question.