make sure the I18nField defaultvalue is not passed by reference

src/c3nav/mapdata/models/locations.py

@@ -81,10 +81,6 @@ class Location(LocationSlug, AccessRestrictionMixin, TitledMixin, models.Model):
     class Meta:
         abstract = True
 
-    def __init__(self, *args, **kwargs):
-        super().__init__(*args, **kwargs)
-        self.titles = self.titles.copy()
-
     def serialize(self, detailed=True, describe_only=False, **kwargs):
         result = super().serialize(detailed=detailed, **kwargs)
         if not detailed: