#8615 fix DeleteUserSubCommand command failed when acl2.0 authenticat…

…ion enabled

auth/src/main/java/org/apache/rocketmq/auth/authentication/manager/AuthenticationMetadataManagerImpl.java

@@ -146,7 +146,10 @@ public CompletableFuture<Void> deleteUser(String username) {
                 throw new AuthenticationException("username can not be blank");
             }
             CompletableFuture<Void> deleteUser = this.getAuthenticationMetadataProvider().deleteUser(username);
-            CompletableFuture<Void> deleteAcl = this.getAuthorizationMetadataProvider().deleteAcl(User.of(username));
+            CompletableFuture<Void> deleteAcl = CompletableFuture.completedFuture(null);
+            if (this.getAuthorizationMetadataProvider() != null) {
+                deleteAcl = this.getAuthorizationMetadataProvider().deleteAcl(User.of(username));
+            }
             return CompletableFuture.allOf(deleteUser, deleteAcl);
         } catch (Exception e) {
             this.handleException(e, result);
@@ -214,9 +217,6 @@ private AuthenticationMetadataProvider getAuthenticationMetadataProvider() {
     }
 
     private AuthorizationMetadataProvider getAuthorizationMetadataProvider() {
-        if (authorizationMetadataProvider == null) {
-            throw new IllegalStateException("The authorizationMetadataProvider is not configured");
-        }
         return authorizationMetadataProvider;
     }
 }