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: If3d480436506ecc5f3c2fcbd51ceaac59f2b7dec
ref: https://hg.python.org/cpython/rev/fe12c34c39eb

oslo_messaging/notify/_impl_routing.py

@@ -13,10 +13,10 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import fnmatch
 import logging
 
 from oslo_config import cfg
+from oslo_utils import fnmatch
 import six
 from stevedore import dispatch
 import yaml