update flask-admin to recent branch

[TomGoBravo]

Update flask-admin to a branch that is only one commit away from the public head. The extra commit is needed as a work-around for pallets-eco/flask-admin#2351

The update fixes

tourist/tests/test_basic.py::test_heavy
  /home/thecap/.pyenv/versions/tourist-3.10.7/lib/python3.10/site-packages/flask_admin/form/widgets.py:2: DeprecationWarning: '_request_ctx_stack' is deprecated and will be removed in Flask 2.4.
    from flask.globals import _request_ctx_stack

thanks to pallets-eco/flask-admin#2286.