Reduce log level for informative message (#203) (#916)

Signed-off-by: Enrico Tröger <enrico.troeger@uvena.de>
(cherry picked from commit e77a7d9)

Co-authored-by: Enrico Tröger <enrico.troeger@uvena.de>

src/main/java/org/opensearch/securityanalytics/indexmanagment/DetectorIndexManagementService.java

@@ -243,6 +243,7 @@ private String executorName() {
     }
 
     private void deleteOldIndices(String tag, String... indices) {
+        logger.info("info deleteOldIndices");
         ClusterStateRequest clusterStateRequest = new ClusterStateRequest()
                 .clear()
                 .indices(indices)