add comment says only one endpoint is supported

Author: mznet

instrumentation/clickhouse/clickhouse-clientv2-0.8/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/clickhouse/clientv2/v0_8/ClickHouseClientV2Instrumentation.java

@@ -58,6 +58,8 @@ public static ClickHouseScope onEnter(
         return null;
       }
 
+      // https://clickhouse.com/docs/integrations/language-clients/java/client#client-configuration
+      // Currently, clientv2 supports only one endpoint.
       String endPoint = client.getEndpoints().stream().findFirst().orElse(null);
       String host = null;
       Integer port = 0;