As of I83b46e223e85306b0e54f1d19cbbc7f21489e759,
glance_image_delete_timeout and glance_image_delete_poll_interval
have been moved from rally.plugins.openstack.wrappers.glance to
rally.plugins.openstack.scenarios.glance.utils. So, if a module
using the options doesn't import the glance.utils module, we should
add import_opt for the options. Otherwise NoSuchOptError might be
raised when the options are being used.
Closes-Bug: 1579855
Change-Id: Ia05be0997680e2c91dc5d19bc6e36d70c6b07690
9f1725b2df