handle APIError for inspect_image

Docker-DCO-1.1-Signed-off-by: Lokesh Mandvekar <lsm5@redhat.com> (github: lsm5)

	modified:   docker/client.py



This is with reference to cstpierre's comment here: https://admin.fedoraproject.org/updates/FEDORA-EPEL-2014-0490/python-docker-py-0.2.3-7.el6