Use debug instead of print for Django and fix indentation, see #1467

jedi/plugins/django.py

@@ -4,6 +4,7 @@ Bugs:
     - Can't infer User model.
     - Can't infer ManyToManyField.
 """
+from jedi import debug
 from jedi.inference.base_value import LazyValueWrapper
 from jedi.inference.utils import safe_property
 from jedi.inference.filters import ParserTreeFilter, DictFilter
@@ -85,9 +86,8 @@ def _infer_field(cls, field):
                     else:
                         return DjangoModelField(value, field).name
 
-    print('django plugin: fail to infer `{}` from class `{}`'.format(
-        field.string_name, cls.name.string_name,
-    ))
+    debug.dbg('django plugin: fail to infer `%s` from class `%s`',
+              field.string_name, cls.name.string_name)
 
 
 def get_metaclass_filters(func):