let test_choose_a_port_for_me pass when service registry is missing, i.e. when not running with rethinkdb

setup.py

@@ -51,7 +51,7 @@ except:
 
 setuptools.setup(
         name='warcprox',
-        version='2.1b1.dev70',
+        version='2.1b1.dev71',
         description='WARC writing MITM HTTP/S proxy',
         url='https://github.com/internetarchive/warcprox',
         author='Noah Levitt',

tests/test_warcprox.py

@@ -1369,23 +1369,24 @@ def test_choose_a_port_for_me(service_registry):
     th = threading.Thread(target=controller.run_until_shutdown)
     th.start()
     try:
-
-        # check that service registry entry lists the correct port
-        start = time.time()
-        ports = []
-        while time.time() - start < 30:
-            svcs = service_registry.available_services('warcprox')
-            ports = [svc['port'] for svc in svcs]
-            if controller.proxy.server_port in ports:
-                break
-        assert controller.proxy.server_port in ports
-
         # check that the status api lists the correct port
         url = 'http://localhost:%s/status' % controller.proxy.server_port
         response = requests.get(url)
         assert response.status_code == 200
         status = json.loads(response.content.decode('ascii'))
         assert status['port'] == controller.proxy.server_port
+
+        if service_registry:
+            # check that service registry entry lists the correct port
+            start = time.time()
+            ports = []
+            while time.time() - start < 30:
+                svcs = service_registry.available_services('warcprox')
+                ports = [svc['port'] for svc in svcs]
+                if controller.proxy.server_port in ports:
+                    break
+            assert controller.proxy.server_port in ports
+
     finally:
         controller.stop.set()
         th.join()