Removed redundant dependency of hp3parclient

This dependency, at first, is unused,
and at second - was removed from
openstack requirements:
https://github.com/openstack/requirements/commit/01ceffe54f9e46c5ee04048c7a1db66960e28eb7
It breaks devstack installation on ci jobs.

Change-Id: I09a3ac8c7f64c6baef74454d98b03daf613cade9