use thread safe fnmatch
use thread safe fnmatch

fnmatch is not thread safe in python <2.7.10, let's use the safe
one in oslo.utils

Change-Id: I489271f8fca94b1a1cb3ad30790042fe7468338c
ref: https://hg.python.org/cpython/rev/fe12c34c39eb

openstack/python-heatclient