[FLINK-11901][build] Update NOTICE files with year 2019

This closes #7975.
diff --git a/flink-connectors/flink-sql-connector-elasticsearch6/src/main/resources/META-INF/NOTICE b/flink-connectors/flink-sql-connector-elasticsearch6/src/main/resources/META-INF/NOTICE
index 9880ee9..4b59538 100644
--- a/flink-connectors/flink-sql-connector-elasticsearch6/src/main/resources/META-INF/NOTICE
+++ b/flink-connectors/flink-sql-connector-elasticsearch6/src/main/resources/META-INF/NOTICE
@@ -1,5 +1,5 @@
 flink-sql-connector-elasticsearch6
-Copyright 2014-2018 The Apache Software Foundation
+Copyright 2014-2019 The Apache Software Foundation
 
 This product includes software developed at
 The Apache Software Foundation (http://www.apache.org/).