Work around bug in python-flask-openid-1.2-1.el7.
Unconstrain Flask.

I dunno what the issue was, but I'm not hitting any login issues anymore
with a modern Flask.
Merge pull request #36 from fedora-infra/feature/unconstrained-flask

Unconstrain Flask.
Merge pull request #35 from fedora-infra/feature/python-flask-openid-1.2-1.el7-workaround

Work around bug in python-flask-openid-1.2-1.el7.
Use the URL root as trust root (needs flask-openid 1.2.4+)