Fix for PAL8325(An exception is raised after clicking on "Add" button of the "Merge nodes" dialog box).
Fix for PAL8325(An exception is raised after clicking on "Add" button of the "Merge nodes" dialog box).

FedoraScientific/salome-smesh,FedoraScientific/salome-smesh,FedoraScientific/salome-smesh,FedoraScientific/salome-smesh