HADOOP-17342. Creating a token identifier should not do kerberos name

resolution. Contributed by Jim Brennan.

(cherry picked from commit af389d989770c4218c24e640f572bc7492f7d4b3)

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/token/delegation/AbstractDelegationTokenIdentifier.java

@@ -49,7 +49,7 @@ extends TokenIdentifier {
   private int masterKeyId = 0;
   
   public AbstractDelegationTokenIdentifier() {
-    this(new Text(), new Text(), new Text());
+    this(null, null, null);
   }
   
   public AbstractDelegationTokenIdentifier(Text owner, Text renewer, Text realUser) {