Make ssl module optional

README.md

@@ -74,6 +74,13 @@ changes
 `light_transition_period` value in seconds to set default transition for light
 switching or light change. Use `0` to remove the transition.
 
+
+### SSL connection
+
+To use SSL connection, you need to set `mqtt_cert` and `mqtt_key`, and optional `mqtt_ca` with corresponding paths to files.
+
+### Custom sensors
+
 You can also use GPIO(s) as binary sensor(s). Add this to configuration:
 
 ```json

lumimqtt/lumimqtt.py

@@ -9,7 +9,6 @@
 from dataclasses import dataclass
 from datetime import datetime
 
-import ssl
 import aio_mqtt
 
 from .__version__ import version
@@ -474,6 +473,8 @@ async def _connect_forever(self) -> None:
                 client_id = f'lumimqtt_{self.dev_id}'
                 context = None
                 if self._mqtt_cert is not None and self._mqtt_key is not None:
+                    import ssl
+
                     context = ssl.SSLContext(ssl.PROTOCOL_TLSv1_2)
                     if self._mqtt_ca is not None:
                         context.load_verify_locations(self._mqtt_ca)