This introduces a common macro to assemble the correct url templates to
avoid code duplication and have the feed config handling in a central place.
Signed-off-by: Jo-Philipp Wich <jow@openwrt.org>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@45799 3c298f89-4303-0410-b956-a3cf2f4a3e73