Fix Update coordinator.py

Fix to kvj#36 (comment)

custom_components/openwrt/coordinator.py

@@ -167,7 +167,10 @@ async def do_file_exec(self, command: str, params, env: dict, extra: dict):
         result = await self._ubus.api_call(
             "file",
             "exec",
-            dict(command=command, params=params, env=env)
+            if env !={}:
+                dict(command=command, params=params, env=env)
+            else:
+                dict(command=command, params=params)
         )
         _LOGGER.debug(f"Execute result: {self._id}: {result}")
         self._coordinator.hass.bus.async_fire(
@@ -326,4 +329,4 @@ def new_coordinator(hass, config: dict, all_devices: dict) -> DeviceCoordinator:
     _LOGGER.debug(f"new_coordinator: {config}, {all_devices}")
     connection = new_ubus_client(hass, config)
     device = DeviceCoordinator(hass, config, connection, all_devices)
-    return device
+    return device