Impersonator tag no longer exists, remove it. And be a bit less racy.

Author: Simon MacMullen

test/src/com/rabbitmq/client/test/functional/UserIDHeader.java

@@ -17,8 +17,8 @@
 package com.rabbitmq.client.test.functional;
 
 import com.rabbitmq.client.AMQP;
+import com.rabbitmq.client.AlreadyClosedException;
 import com.rabbitmq.client.test.BrokerTestCase;
-import com.rabbitmq.tools.Host;
 
 import java.io.IOException;
 
@@ -36,18 +36,8 @@ public void testInvalidUserId() {
             fail("Accepted publish with incorrect user ID");
         } catch (IOException e) {
             checkShutdownSignal(AMQP.PRECONDITION_FAILED, e);
-        }
-    }
-
-    public void testImpersonatedUserId() throws IOException {
-        Host.rabbitmqctl("set_user_tags guest administrator impersonator");
-        connection = null;
-        channel = null;
-        setUp();
-        try {
-            publish(BAD);
-        } finally {
-            Host.rabbitmqctl("set_user_tags guest administrator");
+        } catch (AlreadyClosedException e) {
+            checkShutdownSignal(AMQP.PRECONDITION_FAILED, e);
         }
     }