DeprecationWarning: 'HTMLString' will be removed in WTForms 3.0

[HaloKo4]

Getting this warning:

  /usr/local/lib/python3.6/site-packages/flask_appbuilder/fieldwidgets.py:54: DeprecationWarning: 'HTMLString' will be removed in WTForms 3.0. Use 'markupsafe.Markup' instead.
    template % {"text": html_params(type="text", value=field.data, **kwargs)}

HTMLString needs to be removed from the code

[dpgaspar]

@HaloKo4 agree, I'll make a PR

[fedepad]

@dpgaspar Because of https://github.com/dpgaspar/Flask-AppBuilder/pull/1759 this Issue can be closed, right?