Unchecked unwrap resulting in a panic in JWT handling

[reubenmiller]

Describe the bug

The following log entry shows a panic when unwrapping the JWT token response.

Jul 25 09:41:54 rackfslot2 tedge-mapper[1591753]: thread 'tokio-runtime-worker' panicked at crates/extensions/c8y_auth_proxy/src/tokens.rs:44:72:
Jul 25 09:41:54 rackfslot2 tedge-mapper[1591753]: called `Result::unwrap()` on an `Err` value: NoJwtReceived

Whilst the above panic does not seem to affect the normal operation of the tedge-mapper, however it should be handled to reduce the noise in the logic, as generally a "panic" is viewed as something to fix.

To Reproduce

It is unclear exactly caused the JWT to fail (possibly something to do with the built-in as posted via #2960).

Expected behavior

Panics should be avoided in normal operation and for transient errors (such as a JWT token failing to be returned).

Screenshots

Environment (please complete the following information):

Property	Value
OS [incl. version]	Debian GNU/Linux 12 (bookworm)
Hardware [incl. revision]	Raspberry Pi 4 Model B Rev 1.5
System-Architecture	Linux rackfslot2 6.6.20+rpt-rpi-v8 #1 SMP PREEMPT Debian 1:6.6.20-1+rpt1 (2024-03-07) aarch64 GNU/Linux
thin-edge.io version	tedge 1.1.2~201+g5886e5d

Additional context

[Ruadhri17]

Resolved by #3119

Panic was replaced by error message informing that jwt token could not be retrieved.

[gligorisaev]

it is extremly hard for me to reproduce this bug, so I trust that it was resolved