Fixed a possible NPE that can occur if a test times out before any clients retrieve the test.

Patch by: jlabanca
Review by: jat



git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@6235 8db76d5a-ed1c-0410-87a9-c151d255dfc7
diff --git a/user/src/com/google/gwt/junit/JUnitMessageQueue.java b/user/src/com/google/gwt/junit/JUnitMessageQueue.java
index 57ccd4a..c5a2d10 100644
--- a/user/src/com/google/gwt/junit/JUnitMessageQueue.java
+++ b/user/src/com/google/gwt/junit/JUnitMessageQueue.java
@@ -306,7 +306,7 @@
           buf.append('\n');
         }
 
-        if (!results.containsKey(clientStatus.clientId)) {
+        if (results == null || !results.containsKey(clientStatus.clientId)) {
           buf.append(" - NO RESPONSE: ");
         } else {
           buf.append(" - (ok): ");