TEMPer component: reset devices on address change (#4596)

Fixes https://github.com/home-assistant/home-assistant/issues/4389

The USB address of these devices periodically changes, causing
home-assistant to fail to read the temperature data. This PR fixes this
by re-reading the available devices on failure. I've been running this
for several days and for the first time have consistent temperature
data without having to restart home-assistant.