Allow empty response when an exception is thrown

[andriy-dmytruk]

No description provided.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
77.8% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[graemerocher]

could you add a test here?

[andriy-dmytruk]

could you add a test here?

It would be hard to add a test, as I encountered the issue in oracle cloud and not here.
The only change is response to response == null ? null : response.toMutableResponse(), so it should be safe, though.