[Python-apps-team] Bug#976189: Catfish not starting anymore after installation of Python 3.9

[Niente]

Package: catfish
X-Debbugs-Cc: niente at posteo.de
Version: 1.4.13-1
Severity: grave
Justification: renders package unusable

Dear Maintainer,

    * What led up to the situation?
upgrading Python to 3.9
    * What was the outcome of this action?
Catfish doesn't start anymore:
Traceback (most recent call last):
   File "/usr/bin/catfish", line 44, in <module>
     catfish.main()
   File "/usr/lib/python3/dist-packages/catfish/__init__.py", line 78, in 
main
     window = CatfishWindow.CatfishWindow()
   File "/usr/lib/python3/dist-packages/catfish_lib/Window.py", line 171, 
in __new__
     builder = get_builder(__builder__['ui_file'])
   File "/usr/lib/python3/dist-packages/catfish_lib/helpers.py", line 
109, in get_builder
     builder.add_from_file(ui_filename)
   File "/usr/lib/python3/dist-packages/catfish_lib/Builder.py", line 87, 
in add_from_file
     ele_widgets = tree.getiterator("object")
AttributeError: 'ElementTree' object has no attribute 'getiterator'