Bug 629964 - Make status messages unaffected by JS again, backing out bogus change from bug 574688. a=backout

browser/app/profile/firefox.js

@@ -430,6 +430,8 @@ pref("dom.max_script_run_time",                   20);
 // applications, but without it there isn't a really good way to prevent chrome
 // spoofing, see bug 337344
 pref("dom.disable_window_open_feature.location",  true);
+// prevent JS from setting status messages
+pref("dom.disable_window_status_change",          true);
 // allow JS to move and resize existing windows
 pref("dom.disable_window_move_resize",            false);
 // prevent JS from monkeying with window focus, etc