fix f string

exporter.py

@@ -19,7 +19,7 @@ def fetch_metrics():
 	}
 
 	auth = {
-		'Authorization': f'Bearer {config['token']}'
+		'Authorization': f"Bearer {config['token']}"
 	}
 	room_version_count = {}
 	rooms = requests.get(f"https://{config['synapse_url']}/_synapse/admin/v1/rooms", headers=auth).json()['rooms']