Fix unclosed requests

[gfmio]

This PR fixes the unclosed response warnings that Statefun reports when an HTTP request by Flink fails. These unclosed reqeusts currently spam the logs and result in a small memory leak.

The PR also sets the recommended logger setting to get more details about the issue when it occurs.

Example:

Aug 09, 2023 9:28:57 AM okhttp3.internal.platform.Platform log
Aug 9 10:28:57 <POD> taskmanager WARNING WARNING: A connection to http://worker:9090/ was leaked. Did you forget to close a response body? To see where this was allocated, set the OkHttpClient logger level to FINE: Logger.getLogger(OkHttpClient.class.getName()).setLevel(Level.FINE);