localisation fix for bookmarks, r=jst@citec.fi

xpfe/components/bookmarks/resources/locale/en-US/bookmark.properties

@@ -37,3 +37,7 @@ WebPageTitle = Title:
 WebPageURL = URL:
 WebPageAskDisplay = Would you like to display it?
 WebPageAskStopOption = Stop checking for updates on this web page
+
+pleaseEnterALocation = Please enter a location
+
+