Undefined error in reporter

[qstokkink]

While stress testing Tribler, I ran into an error.

error.response.data.error is undefined
formatAxiosError@http://127.0.0.1:33965/src/services/reporting.ts:30:9
startDownloadFromFile@http://127.0.0.1:33965/src/services/tribler.service.ts:60:14

This is related to the following check:

https://github.com/Tribler/tribler/blob/b48fe77479ef372b5702baa67972f9e8d42f45c2/src/tribler/ui/src/services/reporting.ts#L36-L37

The intention here was to first check if handled was not undefined and then check if it was false. However, the former check is lacking.