Remove H803 of flake8 ignore list in tox
Remove H803 of flake8 ignore list in tox

In hacking >=0.10.0,there is not H803,we should remove it.
For more information:
https://github.com/openstack-dev/hacking/blob/master/setup.cfg

Change-Id: I1d873821f55d8677e834296848e1c0facb51e2ae

openstack/heat-translator,openstack/heat-translator