Use uwsgi binary from path
Use uwsgi binary from path

In-line with devstack patch [1], switch invocations to find uwsgi in the
path.

[1] https://review.opendev.org/#/c/577779/

Change-Id: I5e6aee49f434820881051874c9ad2628b4fcada7

openstack/octavia,openstack/octavia,openstack/octavia