fix(scan): fix err msg when unable to connect via SSH (#702)

scan/debian.go

@@ -62,7 +62,7 @@ func detectDebian(c config.ServerInfo) (itsMe bool, deb osTypeInterface, err err
 			return false, deb, nil
 		}
 		if r.ExitStatus == 255 {
-			return false, deb, fmt.Errorf("Unable to connect via SSH. Check SSH settings. If you have never SSH to the host to be scanned, SSH to the host before scanning in order to add the HostKey. %s@%s port: %s\n%s", c.User, c.Host, c.Port, r)
+			return false, deb, fmt.Errorf("Unable to connect via SSH. Scan with -vvv option to print SSH debugging messages and check SSH settings. If you have never SSH to the host to be scanned, SSH to the host before scanning in order to add the HostKey. %s@%s port: %s\n%s", c.User, c.Host, c.Port, r)
 		}
 		util.Log.Debugf("Not Debian like Linux. %s", r)
 		return false, deb, nil