neutron.tests.unit.common.test_utils.TestThrottler.test_throttler
is failing with "AssertionError: 1 not greater than 1", change the
assert to assertGreaterEqual.
Change-Id: Iba29ab0b1141e731cc811e8bee076dd5726248b5
Closes-Bug: #1916572
(cherry picked from commit b168232e03)