Fixed local demo to include generate_crypto step

[gtoff]

Docker compose mounts local "scripts" folder, including certs/keys.
Hence certs/keys need to be locally generated before launching the composition.

Failure to do so results in both talker and listener failing with:

talker-1        | The application panicked (crashed).
talker-1        |   crypto file not found!: Os { code: 2, kind: NotFound, message: "No such file or directory" }