Revert "using isinstance to add subclass support"

This reverts commit df0c7e9.

objectpath/core/interpreter.py

@@ -42,7 +42,7 @@ def __init__(self, obj, cfg=None):
     if self.D: super(Tree, self).__init__()
 
   def setData(self, obj):
-    if isinstance(obj, tuple(ITER_TYPES + [dict])):
+    if type(obj) in ITER_TYPES + [dict]:
       self.data = obj
 
   def setObjectGetter(self, object_getter_cb):