Handle empty intent mapping in domain

[sentry-io]

Sentry Issue: RASA-OPEN-SOURCE-3PF

Stack Trace

AttributeError: 'NoneType' object has no attribute 'setdefault'
(21 additional frame(s) were not displayed)
...
  File "rasa/shared/core/domain.py", line 177, in from_dict
    return cls(
  File "rasa/shared/core/domain.py", line 527, in __init__
    self.intent_properties = self.collect_intent_properties(
  File "rasa/shared/core/domain.py", line 441, in collect_intent_properties
    intent_name, properties = cls._intent_properties(
  File "rasa/shared/core/domain.py", line 476, in _intent_properties
    cls._transform_intent_properties_for_internal_use(
  File "rasa/shared/core/domain.py", line 322, in _transform_intent_properties_for_internal_use
    properties.setdefault(USE_ENTITIES_KEY, True)

Further Information

This is caused when you have in domain.yml, for example:

intents:
- greet:
- goodbye:

Command or request that led to error:

rasa train