omero.client ensure args is not None

[manics]

c = omero.client('wss://idr.openmicroscopy.org/omero-ws') should work instead of throwing an Exception

[jburel]

Without this PR:
client = omero.client('ws://idr.openmicroscopy.org/omero-ws') or client = omero.client(host='ws://idr.openmicroscopy.org/omero-ws') will throw

ModuleNotFoundError: No module named 'omero_ext.path'

With this PR:
client = omero.client(host='ws://idr.openmicroscopy.org/omero-ws') or client = omero.client('ws://idr.openmicroscopy.org/omero-ws') do not throw.

This used to work on early dev version so this should be included in the coming 5.6 release
This prevents the usage of web socket (e.g. mybinder usage, demo scheduled 23/01)

[joshmoore]

ModuleNotFoundError: No module named 'omero_ext.path'

I'm unsure how this would be related. For me, this suggests that something is out of sync, since this has been fixed separately.

[jburel]

Sorry I was not on master when I first run the command
The error without the PR is

>>> client = omero.client(host='ws://idr.openmicroscopy.org/omero-ws')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/jmarie/Documents/git-repo/omero-py/target/omero/__init__.py", line 67, in client
    return omero.clients.BaseClient(*args, **kwargs)
  File "/Users/jmarie/Documents/git-repo/omero-py/target/omero/clients.py", line 134, in __init__
    args.append(self._get_endpoint_from_hosturl(hosturl))
AttributeError: 'NoneType' object has no attribute 'append'

[jburel]

Tested in notebook too AttributeError: 'NoneType' object has no attribute 'append'
with dev9
Regression between dev4 and dev9