[FLINK-20711][docs] Fix failure-handler parameter enumeration value typo in ES connector doc

This closes #14467
diff --git a/flink-connectors/flink-connector-elasticsearch-base/src/main/java/org/apache/flink/streaming/connectors/elasticsearch/table/ElasticsearchOptions.java b/flink-connectors/flink-connector-elasticsearch-base/src/main/java/org/apache/flink/streaming/connectors/elasticsearch/table/ElasticsearchOptions.java
index 7f437f9..c40b94c 100644
--- a/flink-connectors/flink-connector-elasticsearch-base/src/main/java/org/apache/flink/streaming/connectors/elasticsearch/table/ElasticsearchOptions.java
+++ b/flink-connectors/flink-connector-elasticsearch-base/src/main/java/org/apache/flink/streaming/connectors/elasticsearch/table/ElasticsearchOptions.java
@@ -89,7 +89,7 @@
                                             text(
                                                     "\"ignore\" (ignores failures and drops the request),"),
                                             text(
-                                                    "\"retry_rejected\" (re-adds requests that have failed due to queue capacity saturation),"),
+                                                    "\"retry-rejected\" (re-adds requests that have failed due to queue capacity saturation),"),
                                             text(
                                                     "\"class name\" for failure handling with a ActionRequestFailureHandler subclass"))
                                     .build());