Update __init__.py

Author: hangonlyra

instrumentation/opentelemetry-instrumentation-flask/src/opentelemetry/instrumentation/flask/__init__.py

@@ -238,6 +238,7 @@ def response_hook(span: Span, status: str, response_headers: List):
 API
 ---
 """
+
 from logging import getLogger
 from time import time_ns
 from timeit import default_timer