Fixed #7003 - crash when warranty months or purchase date is null
Fixed #7003 - crash when warranty months or purchase date is null

dmeltzer/snipe-it,uberbrady/snipe-it,ppavlov28/snipe-it,snipe/snipe-it,ppavlov28/snipe-it,uberbrady/snipe-it,mtucker6784/snipe-it,snipe/snipe-it,uberbrady/snipe-it,ppavlov28/snipe-it,snipe/snipe-it,mtucker6784/snipe-it,mtucker6784/snipe-it,dmeltzer/snipe-it,uberbrady/snipe-it,uberbrady/snipe-it,mtucker6784/snipe-it,dmeltzer/snipe-it,dmeltzer/snipe-it,mtucker6784/snipe-it,snipe/snipe-it