Bug#1031765: pgrep: signal handler matching breaks argument parsing

[Heinrich Schuchardt]

Upstream has merged https://github.com/ganeti/ganeti/pull/1692, commit 
9cd67e6a81c6 ("uidpool_unittest: avoid using negative UIDs") to solve 
the issue.

Additionally the following patch is needed to fix a separate problem 
with testing:
a40748ab26fc ("py-tests: make tests compatible with roman 3.2+")
Best regards

Heinrich