bpo-33312: update Tools/gdb/libpython.py to match. (GH-6548)

Tools/gdb/libpython.py

@@ -730,7 +730,7 @@ class PyDictObjectPtr(PyObjectPtr):
         else:
             offset = 8 * dk_size
 
-        ent_addr = keys['dk_indices']['as_1'].address
+        ent_addr = keys['dk_indices'].address
         ent_addr = ent_addr.cast(_type_unsigned_char_ptr()) + offset
         ent_ptr_t = gdb.lookup_type('PyDictKeyEntry').pointer()
         ent_addr = ent_addr.cast(ent_ptr_t)