regviewr.dll should be removed during install

xpinstall/packager/os2/browser.jst

@@ -34,6 +34,7 @@ function upgradeCleanup()
   deleteThisFile("Chrome",     "chrome.rdf");
   deleteThisFolder("Chrome",   "overlayinfo");
   deleteThisFile("Components", "gkhtml.dll");
+  deleteThisFile("Components", "regviewr.dll");
 }
 
 // main