start webhook server

matrix_alertbot/main.py

@@ -54,6 +54,8 @@ def create_matrix_client(config: Config) -> AsyncClient:
 async def start_matrix_client(
     client: AsyncClient, webhook_server: Webhook, cache: Cache, config: Config
 ) -> bool:
+    await webhook_server.start()
+
     # Keep trying to reconnect on failure (with some time in-between)
     while True:
         try: