Add initialization to the new parameter member variable.

Change-Id: I2efcdd002e9ed49371452518c95ea37a2348c3a1
Adding UseHistograms option to procedure and Execute methods

Change-Id: I90b0438b6efed1932c69614ed3f8ad0e1c15a153
Merge topic 'SIMPLEITK-510_AddUseHistogramsOptionToLabelStatistics' into next

01352604 Adding UseHistograms option to procedure and Execute methods
37840d29 Add initialization to the new parameter member variable.