Remove the oslo_utils.fnmatch

Oslo.utils's fnmatch module was added to fix the py2.7 fnmatch module
who was not thread safe [1]. Python 2.7 is no longer supported so now we
can use the stdlib's fnmatch module and deprecate the one of oslo.utils.

[1] https://bugs.python.org/issue23191$

Change-Id: Id5381a0a5216783f0df594b126786947db16a8d1

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
 from stevedore import dispatch
 import yaml