Prevent START STOP UNIT from changing SCSI2SD `started` value.

This fixes an issue where Macs on reboot would stop the drive and never try to restart it. This also matches observed behavior on a Matshita drive, which would just spin down in response to this command and continue to indicate a good response to TEST UNIT READY as long as a disk was in the drive.

src/BlueSCSI_cdrom.cpp

@@ -1521,11 +1521,6 @@ extern "C" int scsiCDRomCommand()
                 cdromPerformEject(img);
             }
         }
-        else
-        {
-            // flow through to disk handler
-            commandHandled = 0;
-        }
     }
     else if (command == 0x25)
     {