Fix H702 pep8 error with latest hacking

nova test job on hacking master is failing
with

2020-02-24 01:14:53.698965 | ubuntu-bionic | ./nova/api/metadata/handler.py:251:55:
H702: Formatting operation should be outside of localization method call

- https://review.opendev.org/#/c/705514/

This is H702 error for localization formatting.

Change-Id: I9eaa90c273327a3ca0ca1722a45017e59e9f0f0c

nova/api/metadata/handler.py

@@ -248,10 +248,10 @@ class MetadataRequestHandler(wsgi.Application):
 
         if len(ports) != 1:
             msg = _('Expected a single port matching provider %(pr)s '
-                    'and IP %(ip)s. Found %(count)d.' % {
+                    'and IP %(ip)s. Found %(count)d.') % {
                         'pr': provider_id,
                         'ip': instance_address,
-                        'count': len(ports)})
+                        'count': len(ports)}
 
             LOG.error(msg)
             raise webob.exc.HTTPBadRequest(explanation=msg)