WebClient doesn't support h2

[geNAZt]

When using WebClient (which is default for spring) the clientConnector built doesn't allow you to set the protocol. Therefore it only supports http/1.1.

Since other clients support http2:

java11: https://github.com/PlaytikaOSS/feign-reactive/blob/develop/feign-reactor-java11/src/main/java/reactivefeign/java11/Java11ReactiveFeign.java#L104 jetty: https://github.com/PlaytikaOSS/feign-reactive/blob/baba570b5039c649d5487883f3db1e183026773a/feign-reactor-jetty/src/main/java/reactivefeign/jetty/JettyReactiveFeign.java#L41

I would love to see that the netty connection builder takes the useHttp2 flag into account: https://github.com/PlaytikaOSS/feign-reactive/blob/develop/feign-reactor-webclient/src/main/java/reactivefeign/webclient/NettyClientHttpConnectorBuilder.java#L73

If wanted i would love to PR this change

Thanks

[kptfh]

please make PR