Updating error message to include new formulation of history frame.

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@1135 8db76d5a-ed1c-0410-87a9-c151d255dfc7
diff --git a/user/src/com/google/gwt/user/client/History.java b/user/src/com/google/gwt/user/client/History.java
index 621b00f..7eefe13 100644
--- a/user/src/com/google/gwt/user/client/History.java
+++ b/user/src/com/google/gwt/user/client/History.java
@@ -56,7 +56,7 @@
       GWT.log(
           "Unable to initialize the history subsystem; did you "
               + "include the history frame in your host page? Try "
-              + "<iframe id='__gwt_historyFrame' style='width:0;height:0;border:0'>"
+              + "<iframe src=\"javascript:''\" id='__gwt_historyFrame' style='width:0;height:0;border:0'>"
               + "</iframe>", null);
     }
   }