discover.sh updated with nmap zero hosts found handling
discover.sh updated with nmap zero hosts found handling

ellipsys/discover,firebitsbr/discover,harayz/discover,bmoar/discover,j4s0nh4ck/discover,harayz/discover,bmoar/discover,EricSB/discover,EricSB/discover,harayz/discover,EricSB/discover,xujun10110/discover,j4s0nh4ck/discover,j4s0nh4ck/discover,ellipsys/discover,firebitsbr/discover,bmoar/discover,xujun10110/discover,ellipsys/discover,xujun10110/discover,firebitsbr/discover