Thread panic when calling `dkms debug kel` on a non-transferable identifier

[daidoji]

I forgot that KELs may or may not be provided for non-transferable identifiers like witnesses and attempted the following command on the current dkms-demo b84670f that was running at the time and queried the first witness as so

daidoji@vLEIDALaptop1:~/ssi/dkms-bin$ ./target/debug/dkms debug kel --source http://172.17.0.1:3234/ --identifier "BDg1zxxf8u4Hx5IPraZzmStfSCZFZbDzMHjqVcFW5OfP" --sn 0
Registering out of order escrow with timeout: 60s

thread 'main' panicked at src/subcommands/debug.rs:75:72:
called `Result::unwrap()` on an `Err` value: Error("expected value", line: 1, column: 1)
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

I can provide the back trace if that helps but I would expect the tool not to panic and just return that no KEL exists or something of the sort when using it erroneously in this manner.