added new line

Author: yayyz

validate-binary-search-tree/yayyz.py

@@ -22,7 +22,4 @@ def is_bst(node):
             return True, min(left_min, node.val), max(right_max, node.val)
 
         valid, _, _ = is_bst(root)
-        return valid
-
-
-        
+        return valid