Remove setting log level in the constructor

[accelerated]

Setting the log level in the producer and consumer constructor can interfere with the user setting the log_level rdkafka option which essentially gets overriden to Err level. It's best to either let the user specify it via log_level rdkafka option or via the KafkaHandleBase::set_log_level api.

As an alternative, we could check if the user has set the log_level option and if so, not call the set_log_level api. But it feels hackish.

[mfontanini]

This makes sense, the log level setting shouldn't have been there from the start. Thanks!