Value for option url is not valid: invalid URI (inappropriate validation of rfc3986)

I have a fresh installed OpenStack Newton environment based on Ubuntu 16.04. I am facing a regression in the Nova module regarding URI parsing.

$ apt list --installed | grep -E 'nova|rfc'
nova-api/xenial-updates,xenial-updates,now 2:14.0.1-0ubuntu1~cloud0 all [installed]
nova-common/xenial-updates,xenial-updates,now 2:14.0.1-0ubuntu1~cloud0 all [installed,automatic]
nova-conductor/xenial-updates,xenial-updates,now 2:14.0.1-0ubuntu1~cloud0 all [installed]
nova-consoleauth/xenial-updates,xenial-updates,now 2:14.0.1-0ubuntu1~cloud0 all [installed]
nova-novncproxy/xenial-updates,xenial-updates,now 2:14.0.1-0ubuntu1~cloud0 all [installed]
nova-scheduler/xenial-updates,xenial-updates,now 2:14.0.1-0ubuntu1~cloud0 all [installed]
python-nova/xenial-updates,xenial-updates,now 2:14.0.1-0ubuntu1~cloud0 all [installed,automatic]
python-novaclient/xenial-updates,xenial-updates,now 2:6.0.0-0ubuntu1~cloud0 all [installed,automatic]
python-rfc3986/xenial,xenial,now 0.2.0-2 all [installed,automatic]

This is an excerpt from my nova.conf:
[neutron]
auth_type = password
auth_uri = http://os-identity:5000
auth_url = http://os-identity:35357
metadata_proxy_shared_secret = XYZ
password = XYZ
project_domain_name = default
project_name = service
region_name = RegionOne
service_metadata_proxy = true
url = http://os-network:9696
user_domain_name = default
username = neutron

The following error is stated in the log:
2016-10-20 08:28:40.251 19479 CRITICAL nova [req-26ab01e7-72b0-4792-a8a4-56454a4c390c - - - - -] ConfigFileValueError: Value for option url is not valid: invalid URI: 'http://os-network:9696'
2016-10-20 08:28:40.251 19479 ERROR nova Traceback (most recent call last):
2016-10-20 08:28:40.251 19479 ERROR nova File "/usr/bin/nova-api", line 10, in <module>
2016-10-20 08:28:40.251 19479 ERROR nova sys.exit(main())
2016-10-20 08:28:40.251 19479 ERROR nova File "/usr/lib/python2.7/dist-packages/nova/cmd/api.py", line 73, in main
2016-10-20 08:28:40.251 19479 ERROR nova launcher.wait()
2016-10-20 08:28:40.251 19479 ERROR nova File "/usr/lib/python2.7/dist-packages/oslo_service/service.py", line 568, in wait
2016-10-20 08:28:40.251 19479 ERROR nova self.conf.log_opt_values(LOG, logging.DEBUG)
2016-10-20 08:28:40.251 19479 ERROR nova File "/usr/lib/python2.7/dist-packages/oslo_config/cfg.py", line 2626, in log_opt_values
2016-10-20 08:28:40.251 19479 ERROR nova _sanitize(opt, getattr(group_attr, opt_name)))
2016-10-20 08:28:40.251 19479 ERROR nova File "/usr/lib/python2.7/dist-packages/oslo_config/cfg.py", line 3057, in __getattr__
2016-10-20 08:28:40.251 19479 ERROR nova return self._conf._get(name, self._group)
2016-10-20 08:28:40.251 19479 ERROR nova File "/usr/lib/python2.7/dist-packages/oslo_config/cfg.py", line 2668, in _get
2016-10-20 08:28:40.251 19479 ERROR nova value = self._do_get(name, group, namespace)
2016-10-20 08:28:40.251 19479 ERROR nova File "/usr/lib/python2.7/dist-packages/oslo_config/cfg.py", line 2711, in _do_get
2016-10-20 08:28:40.251 19479 ERROR nova % (opt.name, str(ve)))
2016-10-20 08:28:40.251 19479 ERROR nova ConfigFileValueError: Value for option url is not valid: invalid URI: 'http://os-network:9696'

The same problem was reported here:
https://bugs.launchpad.net/kolla/+bug/1629729

As it is stated there 'python-rfc3986' could not handle URI which has '-' characters in case of older versions of python-rfc3986 than 0.3.0.

A current workaround is to use e.g. the ip address instead of a hostname or alias that has a hyphen in its name.

The same problem exists in nova-compute on my compute node using:
[vnc]
enabled = true
novncproxy_base_url = https://os-cloud.mycompany.com:6080/vnc_auto.html
vncserver_listen = 0.0.0.0

The setting causes the same invalid uri exception as stated above.

We need a new version of 'python-rfc3986'.