Fix excluded path config behavior

extensions-core/druid-kerberos/src/main/java/io/druid/security/kerberos/KerberosAuthenticator.java

@@ -230,6 +230,12 @@ public class KerberosAuthenticator implements Authenticator
 
         String path = ((HttpServletRequest) request).getRequestURI();
         if (isExcluded(path)) {
+          // For excluded paths that does NOT need to be autheticated.
+          // set authenticated username as Anonymous
+          request.setAttribute(
+              AuthConfig.DRUID_AUTHENTICATION_RESULT,
+              new AuthenticationResult(AuthenticationToken.ANONYMOUS.getName(), authorizerName, null)
+          );
           filterChain.doFilter(request, response);
         } else {
           String clientPrincipal = null;