Fix race condition in async_select_source()

Fixes #23

Author: Jalle19

custom_components/extron/media_player.py

@@ -203,4 +203,5 @@ def create_source_bidict(self) -> bidict:
         return make_source_bidict(num_sources, self._input_names)
 
     async def async_select_source(self, source: str):
-        await self._hdmi_switcher.select_input(self._source_bidict.inverse.get(source))
+        async with self._hdmi_switcher._device.connection():
+            await self._hdmi_switcher.select_input(self._source_bidict.inverse.get(source))