OpenStack os_image is_public flag does not make image public in Glance V1 API

Ubuntu 16.04 (Xenial)
python-shade 1.5.1-0ubuntu1
ansible 2.1.2.0-1ppa~xenia

I tried to upload an image to Glance in OpenStack Icehouse with Ansible:

...
  - name: Upload image to Glance
    os_image:
      name: "{{ distro }}-server-amd64-{{ date }}"
      state: present
      is_public: True
      container_format: bare
      disk_format: qcow2
      filename: "{{ distro }}-server-cloudimg-amd64-disk1.img"

The image is there but property 'is_public' is false. Looking after https://anonscm.debian.org/cgit/python-modules/packages/python-shade.git/tree/shade/openstackcloud.py?h=upstream#n1964
the parameter get lost. Something like this would work:

                if 'is_public' in kwargs:
                    image_kwargs['is_public'] = kwargs.pop('is_public')