Function labjack_retry_delay_from_env 

pub(crate) fn labjack_retry_delay_from_env() -> Duration

Reads the delay between sampler restarts after a failed run.

Reads STREAMER_LABJACK_RETRY_DELAY_SECS in whole seconds. A missing or unparsable value gives the default of 5 s. 0 is accepted and means no delay.