Fix Fine Offset clock overflow on invalid data

src/devices/fineoffset_wh1080.c

@@ -241,7 +241,7 @@ static int fineoffset_wh1080_callback(r_device *decoder, bitbuffer_t *bitbuffer)
                 NULL);
     }
     else if (msg_type == 1) {
-        char clock_str[20];
+        char clock_str[23];
         sprintf(clock_str, "%04d-%02d-%02dT%02d:%02d:%02d",
                 year, month, day, hours, minutes, seconds);