Only pass ipam parameter to create_network() if needed. (#48735)

lib/ansible/modules/cloud/docker/docker_network.py

@@ -424,6 +424,11 @@ class DockerNetworkManager(object):
                     else:
                         ipam_pools.append(utils.create_ipam_pool(**ipam_pool))
 
+            if self.parameters.ipam_driver or ipam_pools:
+                # Only add ipam parameter if a driver was specified or if IPAM parameters
+                # were specified. Leaving this parameter away can significantly speed up
+                # creation; on my machine creation with this option needs ~15 seconds,
+                # and without just a few seconds.
                 if HAS_DOCKER_PY_2 or HAS_DOCKER_PY_3:
                     params['ipam'] = IPAMConfig(driver=self.parameters.ipam_driver,
                                                 pool_configs=ipam_pools)