Fix mikeboers#64: compatibility with Flask 2.2.0+

Author: jnguiot

flask_images/core.py

@@ -429,7 +429,7 @@ def handle_request(self, path):
             image.save(cache_file, format, quality=quality)
             cache_file.close()
 
-        return send_file(cache_path, mimetype=mimetype, cache_timeout=cache_timeout)
+        return send_file(cache_path, mimetype=mimetype, max_age=cache_timeout)