STORM-3632 reduce SimpleSaslServerCallbackHandler logging
diff --git a/storm-client/src/jvm/org/apache/storm/security/auth/sasl/SimpleSaslServerCallbackHandler.java b/storm-client/src/jvm/org/apache/storm/security/auth/sasl/SimpleSaslServerCallbackHandler.java
index 5962eda..462e872 100644
--- a/storm-client/src/jvm/org/apache/storm/security/auth/sasl/SimpleSaslServerCallbackHandler.java
+++ b/storm-client/src/jvm/org/apache/storm/security/auth/sasl/SimpleSaslServerCallbackHandler.java
@@ -168,7 +168,7 @@
                 zid = tmp.getFirst();
                 allowImpersonation = allowImpersonation && tmp.getSecond();
             }
-            LOG.info("Successfully authenticated client: authenticationID = {} authorizationID = {}",
+            LOG.debug("Successfully authenticated client: authenticationID = {} authorizationID = {}",
                      nid, zid);
 
             //if authorizationId is not set, set it to authenticationId.