Update doubly_linked_list_two.py

Author: MaximSmolskiy

Diff for: data_structures/linked_list/doubly_linked_list_two.py

@@ -141,7 +141,7 @@ def delete_value(self, value):
                 self.head = self.head.get_next()
 
             if node == self.tail:
-                self.tail = self.tail.get_previous()
+                self.tail = self.tail.previous
 
             self.remove_node_pointers(node)