public void setBootstrapServer(final String bootstrapServer) {
            this.bootstrapServer = bootstrapServer;
        }
set kafka nameserver address.

@param bootstrapServer kafka nameserver address
shenyu-plugin/shenyu-plugin-logging/shenyu-plugin-logging-kafka/src/main/java/org/apache/shenyu/plugin/logging/kafka/config/KafkaLogCollectConfig.java