Pod system-app-hook-pre in Crashloopbackoff while restoring 3scale backups

Issue

• When in step 5.6.8. Restore system-app pod-system-app is stuck on sequence 1, and pod system-app-hook-pre goes to Crashloopbackoff state.

//From system-app-10-hook-pre-lifecycle logs:

2021-06-09T06:44:52.052496558Z ActiveMerchant MODE set to 'production'
2021-06-09T06:44:52.090124572Z No valid API key has been set, notifications will not be sent
2021-06-09T06:44:52.100081804Z [Core] Using http://backend-listener:3000/internal/ as URL
2021-06-09T06:44:52.548169659Z OpenIdAuthentication.store is nil. Using in-memory store.
2021-06-09T06:44:53.966182764Z [core] non-native log levels verbose, notice, critical emulated using UNKNOWN severity
2021-06-09T06:44:53.969359348Z [core] <== 401 GET status [] (0.003467142) - ThreeScale::Core::APIClient::JSONError: unacceptable content-type text/plain (): 
2021-06-09T06:44:53.969420539Z rake aborted!
2021-06-09T06:44:53.969420539Z ThreeScale::Core::APIClient::JSONError: ThreeScale::Core::APIClient::JSONError: unacceptable content-type text/plain ():