Update mqttd hal code, can control relay now

Guo Wenxue

2019-06-27 b64d6ff04401ed85fce543b8e20c8c360fb284f5

 mqttd/hal/hal.c

@@ -15,13 +15,18 @@

int hal_init(void)
{
    wiringPiSetup();

    init_led(); 
    
    init_relay();

#if 0
    if( sht2x_init() < 0 )
    {
        log_err("Initialise SHT20 failure\n");
        return -2;
    } 
#endif
    
    return 0;
}