cannot choose SLP as device discovery in hp-setup CLI interactive mode

[Yiu-Chung Lee]

hplip version: 3.10.2
Symptom: I have a JetDirect device, which only supports SLP for device discovery. When I run hp-setup in CLI interactive mode, it forces network discovery using mdns, which didn't find my JetDirect. I have to modify the hp-setup script line 336 from
    device_uri = mod.getDeviceUri(device_uri, devices=device.probeDevices(bus))
to
    device_uri = mod.getDeviceUri(device_uri, devices=device.probeDevices(bus, 5, 4, None, '', 'slp'))

to have my JetDirect discovered by hp-setup.