Prevent decrypt to be run with an undefined secret.
Catch sodium decrypt errors.
Merge pull request #101 from mozilla-services/1037604-decryptHawkIdError

Bug 1037604 — Catch sodium decrypt errors.
Fix indentation and retries.
Use Array::some.
Fix smsGatewayResetTimer documentation.
Add the --fd argument to let circus give it to MSISDN-Gateway.