Submitting feedback to imprint in non-existing language breaks the feedback list

[timobrembeck]

Describe the Bug

When feedback is submitted about a fallback translation of the imprint, the feedback list breaks

Steps to Reproduce

1. Submit feedback about imprint in a language where no imprint exists
2. Open feedback list

Expected Behavior

The feedback should be shown

Actual Behavior

An internal server error occurs:

AttributeError: 'NoneType' object has no attribute 'title'

Additional Information

Traceback

_render
  return self.nodelist.render(context)
File "/opt/integreat-cms/.venv/lib/python3.9/site-packages/django/template/base.py", line 938, in render
  bit = node.render_annotated(context)
File "/opt/integreat-cms/.venv/lib/python3.9/site-packages/django/template/base.py", line 905, in render_annotated
  return self.render(context)
File "/opt/integreat-cms/.venv/lib/python3.9/site-packages/django/template/loader_tags.py", line 62, in render
  result = block.nodelist.render(context)
File "/opt/integreat-cms/.venv/lib/python3.9/site-packages/django/template/base.py", line 938, in render
  bit = node.render_annotated(context)
File "/opt/integreat-cms/.venv/lib/python3.9/site-packages/django/template/base.py", line 905, in render_annotated
  return self.render(context)
File "/opt/integreat-cms/.venv/lib/python3.9/site-packages/django/template/loader_tags.py", line 62, in render
  result = block.nodelist.render(context)
File "/opt/integreat-cms/.venv/lib/python3.9/site-packages/django/template/base.py", line 938, in render
  bit = node.render_annotated(context)
File "/opt/integreat-cms/.venv/lib/python3.9/site-packages/django/template/base.py", line 905, in render_annotated
  return self.render(context)
File "/opt/integreat-cms/.venv/lib/python3.9/site-packages/django/template/defaulttags.py", line 214, in render
  nodelist.append(node.render_annotated(context))
File "/opt/integreat-cms/.venv/lib/python3.9/site-packages/django/template/base.py", line 905, in render_annotated
  return self.render(context)
File "/opt/integreat-cms/.venv/lib/python3.9/site-packages/django/template/base.py", line 988, in render
  output = self.filter_expression.resolve(context)
File "/opt/integreat-cms/.venv/lib/python3.9/site-packages/django/template/base.py", line 671, in resolve
  obj = self.var.resolve(context)
File "/opt/integreat-cms/.venv/lib/python3.9/site-packages/django/template/base.py", line 796, in resolve
  value = self._resolve_lookup(context)
File "/opt/integreat-cms/.venv/lib/python3.9/site-packages/django/template/base.py", line 837, in _resolve_lookup
  current = getattr(current, bit)
File "/opt/integreat-cms/.venv/lib/python3.9/site-packages/integreat_cms/cms/models/feedback/imprint_page_feedback.py", line 23, in object_name
  return self.region.imprint.get_translation(self.language.slug).title
AttributeError: 'NoneType' object has no attribute 'title'