[packages] olsrd: don't try to start smartgw if not all deps are installed
if kmod-ipip is missing, there is no need to invoke an expensive operation.
Signed-off-by: Bastian Bittorf <bittorf@bluebottle.com>
git-svn-id: svn://svn.openwrt.org/openwrt/packages/net/olsrd@35679 3c298f89-4303-0410-b956-a3cf2f4a3e73