Incident: Jenkins misconfiguration for arm-fanned

[rvagg]

Tracked the build failures @MylesBorins was experiencing @ nodejs/node#22184 to a misconfiguration in Jenkins:

There's too much activity in the config history to figure out who is responsible for this. It could be me from the last time I removed arm-fanned from CI due to an extended outage and then perhaps I put it back in again wrong but I think the last time I had to do that was in May? But regardless of who, here's the problem: "Parameters from properties file" is essential because it's the mechanism that's used to make parameters flow all the way down to these sub-jobs. Without these parameters we get the default. So from whenever this was enacted, arm-fanned has been testing master for every job submitted to it. Great for ccache, not so great for getting confidence around our tests on ARM!

Fixed now, this is just FYI and FTR.

[refack]

1. FYI & FTR, it should be "safer" to use the Disabled checkbox to disable a job during an outage. Alternativly, if possible try using the Restore old config button.
2. Seems like node-test-commit-arm was still disabled (after I disabled it on 2018-07-25 due to a packetnet outage 🤦‍♂️). I just now enabled it and testing that it hasn't rotted.