Docker entrypoint - fixes and error handling

Fixes a few stupid errors and improve the entrypoint to handle better the case where '/etc/duniter' is not a persistent volume.

And add a DEBUG_ENTRYPOINT boolean variable to enable set -x in the entrypoint.

@librelois same player, shoot again! :)

enabled an automatic merge when the pipeline for e4f07e3b succeeds

approved this merge request

@pini-gh ok cette fois c'est bon :)

Ouf ! :)

mentioned in commit ab7886db

merged