out_kafka: increase max kafka dynamic topic length to 249 characters

This commit increases the max length of kafka dynamic topics.

As the limit previously set (64) seemed arbitrary, and kafka allows for
a maximum of 249 characters per topic, I think fluentbit should reflect
that limit.

Signed-off-by: Michael Meunier <mmeunier@skilld.cloud>

plugins/out_kafka/kafka.c

@@ -227,9 +227,9 @@ int produce_message(struct flb_time *tm, msgpack_object *map,
                             flb_warn("',' not allowed in dynamic_kafka topic names");
                             continue;
                         }
-                        if (val.via.str.size > 64) {
-                            /* Don't allow length of dynamic kafka topics > 64 */
-                            flb_warn(" dynamic kafka topic length > 64 not allowed");
+                        if (val.via.str.size > 249) {
+                            /* Don't allow length of dynamic kafka topics > 249 */
+                            flb_warn(" dynamic kafka topic length > 249 not allowed");
                             continue;
                         }
                         dynamic_topic = flb_malloc(val.via.str.size + 1);