Bug 799465 - Register Filter Today radio buttons don't work correctly

There was a typo in the callback for identifying the required widget to
get the correct value as start_date_today instead of end_date_today.

gnucash/gnome/gnc-plugin-page-register.cpp

@@ -2845,7 +2845,7 @@ get_filter_times (GncPluginPageRegister* page)
     else
     {
         if (gtk_toggle_button_get_active (GTK_TOGGLE_BUTTON (
-                                              priv->fd.start_date_today)))
+                                              priv->fd.end_date_today)))
         {
             priv->fd.end_time = gnc_time64_get_today_end();
         }