Revert "adding the option of defining a filterset_class in the Meta class"

This reverts commit 9b1c1b4.

Author: tangerilli

graphene_django/filter/fields.py

@@ -48,11 +48,7 @@ def args(self, args):
 
     @property
     def filterset_class(self):
-        if self.node_type()._meta.filterset_class:
-            filterset_class = self.node_type()._meta.filterset_class
-        else:
-            filterset_class = get_filterset_class(self._filterset_class, **self.meta)
-        return filterset_class
+        return get_filterset_class(self._filterset_class, **self.meta)
 
     @property
     def filtering_args(self):

graphene_django/types.py

@@ -58,8 +58,7 @@ def __new__(cls, name, bases, attrs):
             only_fields=(),
             exclude_fields=(),
             interfaces=(),
-            registry=None,
-            filterset_class=None
+            registry=None
         )
         if DJANGO_FILTER_INSTALLED:
             # In case Django filter is available, then