Do not require ICategorization behavior on folder contents properties form

[thet]

After removing the ICategorization behavior from File and Image types, I encountered a problem when editors were trying to manipulate images via the properties page. They got this error:

1549886058.340.671272700427 https://hda-graz.at/programm/veranstaltungsfotos/mostlikely-sudden-workshop/@@fc-properties
Traceback (innermost last):
  Module ZPublisher.Publish, line 138, in publish
  Module ZPublisher.mapply, line 77, in mapply
  Module ZPublisher.Publish, line 48, in call_object
  Module bda.aaf.site.browser.foldercontents_actions_properties, line 40, in __call__
  Module plone.app.content.browser.contents.properties, line 93, in __call__
  Module plone.app.content.browser.contents, line 127, in __call__
  Module plone.app.content.browser.contents.properties, line 160, in action
  Module bda.aaf.site.browser.foldercontents_actions_properties, line 66, in dx_action
  Module plone.app.content.browser.contents.properties, line 109, in dx_action
TypeError: ('Could not adapt', <Image at /Plone/hda/programm/veranstaltungsfotos/mostlikely-sudden-workshop/190130_vortrag-buchpraesentation-most-likely_-c-thomas-raggam-hda-6.jpg>, <SchemaClass plone.app.dexterity.behaviors.metadata.ICategorization>)

Here, this line:

plone.app.content/plone/app/content/browser/contents/properties.py

Line 106 in 13f04fa

behavior_categorization = ICategorization(obj)

should read:

 behavior_categorization = ICategorization(obj, None)