refactor: OAuth - redirect direct to provider if just one provider exists (#1618)
refactor: OAuth - redirect direct to provider if just one provider exists (#1618)

* Redirect direct to provider if just one provider exists

* Format using black

Co-authored-by: Daniel Vaz Gaspar <6b96e20e74b52a7d2c8e474c76f6acebac9fc8f6@gmail.com>
dpgaspar/Flask-AppBuilder,dpgaspar/Flask-AppBuilder,dpgaspar/Flask-AppBuilder,dpgaspar/Flask-AppBuilder