Not getting any metrics

Hi,

One of my smart plugs (H110, hardware version 4.1, firmware version 1.1.0) is not returning on any metrics. It used to work before, but I had to move the plug and when I plugged it back in, I stopped receiving metrics for it.

Here is what I see on Prometheus.

```
# HELP kasa_online Device online.
# TYPE kasa_online gauge
kasa_online 0
```
I am currently using the `tplink-plug-exporter_0.4.0_linux_armv7.tar.gz` of the exporter on a Raspberry PI 4. my other two plugs seem to be fine ( I can see metrics for them). But they are on hardware version 1.0 and firmware version 1.2.6, not sure if that has a impact. All three plugs are on the same 2.4GH network.

In the logs I see the following

```
level=error msg="error collecting 192.168.1.181 : system.get_sysinfo: dial tcp 192.168.1.181:9999: connect: connection refused" source=
```

I can see data for all free plus when using the Kasa app on my Android device,