No warning in case when ISet containing more than 1 node is merged with another ISet having different number of moves

[PARAG00991]

Steps to reproduce the issue:

1. Create a tree as shown below:
   
2. Now merge the 2 nodes in 1 ISet as shown:
   
3. Now try to merge the ISet of 2 nodes with the node below it(i.e. with the farthest node from root):
   
   It should have given us a warning message as Couldn't merge the information sets.Please select two information sets with same number of moves but it does nothing.