luci-app-firewall: redirect to overview page on zone details save

This fixes an inconsistency because on the interface configuration if
you press Save&Apply it will go back to overview page.  It is also the
case with "Firewall - Traffic Rules" details.  On firewall zone it only
goes back to firewall zone-detail. Same behaviour on all pages is a good
user experience.

Signed-off-by: Florian Eckert <Eckert.Florian@googlemail.com>
Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>

applications/luci-app-firewall/luasrc/model/cbi/firewall/zone-details.lua

@@ -68,12 +68,6 @@ function name.write(self, section, value)
 		out.exclude = value
 		inp.exclude = value
 	end
-
-	m.redirect = ds.build_url("admin/network/firewall/zones", value)
-	m.title = "%s - %s" %{
-		translate("Firewall - Zone Settings"),
-		translatef("Zone %q", value or "?")
-	}
 end
 
 p = {