Update lux_helper.py

Try fix #259

custom_components/luxtronik/lux_helper.py

@@ -6,6 +6,7 @@
 import struct
 import threading
 import time
+import asyncio
 
 from async_timeout import timeout
 
@@ -276,7 +277,7 @@ def _write(self):
         # Flush queue after writing all values
         self.parameters.queue = {}
         # Give the heatpump a short time to handle the value changes/calculations:
-        time.sleep(WAIT_TIME_WRITE_PARAMETER)
+        await asyncio.sleep(WAIT_TIME_WRITE_PARAMETER)
 
     def _read_parameters(self):
         data = []