Delete the three-space branch from the ps parser

[SimonCropp]

ps -o pid,command has exactly one separator, so everything after the first
space is the command. The branch looking for a run of three spaces is left over
from a format that also carried TIME, and it was wrong in two ways at once.

It sliced timeAndCommandString by firstSpace - the PID's digit count, which is
not an index into that string at all - and then applied the index it found to
the unsliced span. So a command containing three consecutive spaces was
truncated to whatever followed them, and a seven digit PID with a short command
indexed past the end and threw ArgumentOutOfRangeException.

That throw comes out of ProcessCleanup's static constructor, so it is not one
bad line skipped: it is every launch and every kill in the process, permanently.

Two tests, both failing before this: a command with a run of spaces in it, and a
long PID with a short command.