bug#36206: [PATCH] Change `user-error' docstring from "pilot error" to "user error"

[Juri Linkov]

>> Please don't change. "Pilot error" is a known term, see
>> <http://www.hacker-dictionary.com/terms/pilot-error>.
>
> That is unfortunately not what Wikipedia or Google will show a
> confused user, not even when searching e.g. "pilot error software".
> So besides hacker lore, which only a subset of our users will be very
> familiar with, what is the benefit of using this term?

Better to rename it to PMAC error (Problem exists between Monitor And Chair :)