Comment 1 for bug 1902873

Reviewed: https://review.opendev.org/761654
Committed: https://git.openstack.org/cgit/openstack/python-manilaclient/commit/?id=aeb47213eaa8f27bea43bb6b915d6be255a9e246
Submitter: Zuul
Branch: master

commit aeb47213eaa8f27bea43bb6b915d6be255a9e246
Author: Eduardo Santos <email address hidden>
Date: Thu Nov 5 18:27:55 2020 +0000

    Fix undesirable raw Python error

    Using the manilaclient without a subcommand while
    passing an optional argument triggers the raw Python
    error `ERROR: 'Namespace' object has no attribute
    'func'`. This bug can be reproduced by issuing the
    command `manila --os-cache`.
    Added a default value to `func` and an empty value to
    `command` as placeholders so that a help message is
    shown instead of the Python error.
    This patch uses the same fix implemented in the
    python-cinderclient.

    Closes-Bug: #1902873
    Change-Id: I5fcafd4bdfb40b2054e1205c14493c2f4be1f77a