Update merge-two-array.py

Author: Fr4nc3

leetcode/merge-two-array.py

@@ -1,8 +1,8 @@
 # Definition for singly-linked list.
-# class ListNode(object):
-#     def __init__(self, val=0, next=None):
-#         self.val = val
-#         self.next = next
+class ListNode(object):
+    def __init__(self, val=0, next=None):
+        self.val = val
+        self.next = next
 class Solution:
     def mergeTwoLists(self, l1, l2):
         # maintain an unchanging reference to node ahead of the return node.