Implement reset-improvement suggestion

Author: bouwew

plugwise_usb/nodes/helpers/pulses.py

@@ -167,7 +167,9 @@ def pulse_counter_reset(self) -> bool:
     def reset(self) -> None:
         """Reset PulseCollection after an energy-logs reset."""
         # Keep mac, wipe every other attribute.
-        self.__dict__.update(PulseCollection(self._mac).__dict__)
+        fresh_state = PulseCollection(self._mac).__dict__
+        self.__dict__.clear()  # remove *all* existing keys first
+        self.__dict__.update(fresh_state)
 
     def collected_pulses(
         self, from_timestamp: datetime, is_consumption: bool