Fix typo in logging

Author: bouwew

plugwise_usb/nodes/helpers/counter.py

@@ -326,5 +326,5 @@ def update(
         self._pulses = pulses
 
         energy = self.energy
-        _LOGGER.debug("energy=%s or last_update=%s", energy, last_update)
+        _LOGGER.debug("energy=%s on last_update=%s", energy, last_update)
         return (energy, last_reset)