Fixes lost exception when UCEH and UCEH for test are both null

Patch 5416 suppose to report exceptions when UCEH is null however it was only working
when UCEH is null and UCEH for test was set.
I guess I never tested it after initial pass :/

Change-Id: I79f9bdcb8d65fe801b5f1043a837d33d6fc288a0
diff --git a/user/src/com/google/gwt/core/client/impl/Impl.java b/user/src/com/google/gwt/core/client/impl/Impl.java
index 3951b04..f138450 100644
--- a/user/src/com/google/gwt/core/client/impl/Impl.java
+++ b/user/src/com/google/gwt/core/client/impl/Impl.java
@@ -208,11 +208,10 @@
     }
 
     UncaughtExceptionHandler handler = GWT.getUncaughtExceptionHandler();
-    if (handler == Impl.uncaughtExceptionHandlerForTest) {
-      return; // Already reported so we're done.
-    }
-
     if (handler != null) {
+      if (handler == Impl.uncaughtExceptionHandlerForTest) {
+        return; // Already reported so we're done.
+      }
       // TODO(goktug): Handler might throw an exception but catching and reporting it to browser
       // here breaks assumptions of some existing hybrid apps that uses UCE for exception
       // conversion. We don't have an alternative functionality (yet) and it is too risky to include