fix self test after anode/cathode pins swapped in code
fix self test after anode/cathode pins swapped in code

lancernet/Espruino,lancernet/Espruino,luetgendorf/Espruino,lancernet/Espruino,lancernet/Espruino,luetgendorf/Espruino,luetgendorf/Espruino,luetgendorf/Espruino,luetgendorf/Espruino,luetgendorf/Espruino,luetgendorf/Espruino,lancernet/Espruino,lancernet/Espruino,lancernet/Espruino