YARN-10879. Incorrect WARN text in ACL check for application tag based placement (#5231)

Change-Id: Id892e38fe4c834b1743a0df2f0a40146d3d5a878

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/RMAppManager.java

@@ -955,7 +955,7 @@ public class RMAppManager implements EventHandler<RMAppManagerEvent>,
               .checkAccess(callerUGI, QueueACL.SUBMIT_APPLICATIONS, queue)) {
         usernameUsedForPlacement = userNameFromAppTag;
       } else {
-        LOG.warn("User '{}' from application tag does not have access to " +
+        LOG.warn("Proxy user '{}' from application tag does not have access to " +
                 " queue '{}'. " + "The placement is done for user '{}'",
                 userNameFromAppTag, queue, user);
       }