NettyHeadersAdapter::putAll uses HttpHeaders::add, which does not overwrite existing headers. putAll should use HttpHeaders::set instead, just like NettyHeadersAdapter::put does. Closes gh-27887
NettyHeadersAdapter::putAll uses HttpHeaders::add, which does not overwrite existing headers. putAll should use HttpHeaders::set instead, just like NettyHeadersAdapter::put does. Closes gh-27887