Fix processutils.execute errors on windows

Added a check for existence of geteuid.

This fix is related to oslo-incubator commit:
d6a963e911b8456c06dceb5ee3cc88a70c08bf82

Closes-Bug: #1209410

Change-Id: Ibaa1f061bf161768890d4708dc945180121726f9
Merge "Fix processutils.execute errors on windows"