Update plus-one-linked-list.py

Author: kamyu104

Diff for: Python/plus-one-linked-list.py

@@ -20,7 +20,7 @@ def plusOne(self, head):
         dummy = ListNode(0)
         dummy.next = head
 
-        left, right = dummy, dummy
+        left, right = dummy, head
         while right.next:
             if right.val != 9:
                 left = right