update mqttd, test SHT2X support ok

Guo Wenxue

2019-07-31 bb08fc172f25c751902b9a849fc5188f91d362f7

 apue/2.Socket/ds18b20.c

@@ -98,5 +98,7 @@
    /* convert string value to float value */
    *temp = atof(ptr)/1000;
   
    close(fd);

    return 0;
}