Description of problem:

Failing to connect glance as external provider via rest api

Version-Release number of selected component (if applicable):
ovirt-engine-4.1.0-0.2.master.20161209151204.git26a385e.el7.centos.noarch

How reproducible:
100%

Steps to Reproduce:
1. add glance via api
2.
3.

Actual results:
AttributeError: 'OpenStackImageProvider' object has no attribute 'set_read_only'
and the automation is unable to add the glance

Expected results:
glance should get connected

Additional info:
this attribute exists in 4.0

this is how we build the object
self.osp_obj.set_name(self.name)
self.osp_obj.set_url(self.url)
self.osp_obj.set_requires_authentication(self.requires_authentication)
self.osp_obj.set_username(self.username)
self.osp_obj.set_password(self.password)
self.osp_obj.set_authentication_url(self.authentication_url)
self.osp_obj.set_tenant_name(self.tenant_name)
self.osp_obj.set_read_only(self.read_only)