out_rdkafka2: add patch for new version of rdkafka

[ttych]

All PR are failing now because of rdkafka gem update.

The current code works with rdkafka 0.12.0, and in 0.14.0 (there is no 0.13.0), the Rdkafka::Producer implementation has changed, no more @client and Rdkafka::Producer::Client, now there is a @native_client and Rdkafka::NativeKafka.

No update on this part of the code between 0.14.0 and 0.15.0.

There is a constraint in the out_rdkafka2, on the Rdkafka::Producer#close, to add a timeout, which is not part of the standard gem.

I try to update this behavior since following the current way to patch.

Thanks.

[ttych]

I just see #500, so this is not a safe way to do it this way.

and also, waterdrop encapsulation for rdkafka is just for producer side.