Massive logging of missed jobs in v0.1.12

[MattBianco]

supercronic-linux-amd64 with SHA1SUM=048b95b48b708983effb2e5c935a1ef8483d9e3e
I just had my /var/lib/docker/overlay2 filesystem in my production swarm filled to 100% because of millions of messages like:

time="2021-12-03T09:24:42+01:00" level=warning msg="job took too long to run: it should have started -2562047h47m16.854775808s ago" job.command="printf '%(%c)T' -1 > /tmp/cron.running" job.position=0 job.schedule="* 12,13 16 11 2 2021"

10 GB log space consumed in less than 1 minute.

(The schedule in the crontab was set like this in a base image so that the task would only be run during the building/testing of the base image, and not run in containers that use the base image without overwriting the crontab).