Revert "Fix uid check when requesting a jobid from a pid."

This reverts commit d3141dc9.

Bug 4655

Turns out there are many ways to get this information directly from
the slurmstepd.  As you can already get this information from ps we
decided to just revert back to the old non-authenticated way of doing
things.

If we do need this in the future we need to patch the stepd as well as
the slurmd here in all the RPC's that try to grab this.

A user could easily run scontrol (or their own home baked thing)
on the node which will give them a direct contact with the slurmstepd.