Update hand.py
Update hand.py

Fixed issue when no water found in that tile (in Kenya for example)

RCMRD/FloodMapsWorkshop,vightel/FloodMapsWorkshop,pmav99/FloodMapsWorkshop,pmav99/FloodMapsWorkshop,vightel/FloodMapsWorkshop,vightel/FloodMapsWorkshop,pmav99/FloodMapsWorkshop,vightel/FloodMapsWorkshop,pmav99/FloodMapsWorkshop,RCMRD/FloodMapsWorkshop,RCMRD/FloodMapsWorkshop,pmav99/FloodMapsWorkshop,RCMRD/FloodMapsWorkshop,pmav99/FloodMapsWorkshop,RCMRD/FloodMapsWorkshop,RCMRD/FloodMapsWorkshop