Updates the l3.filters proxy to use /usr/bin/ instead
of /usr/local/bin. This should be a more distro friendly
default and follows the pattern used by other OpenStack
services as well.
Change-Id: I8fbaa49f97f5367c112dc399db838d204af7b4c8
route: CommandFilter, /sbin/route, root
# metadata proxy
-metadata_proxy: CommandFilter, /usr/local/bin/quantum-ns-metadata-proxy, root
+metadata_proxy: CommandFilter, /usr/bin/quantum-ns-metadata-proxy, root
kill_metadata7: KillFilter, root, /usr/bin/python2.7, -9
kill_metadata6: KillFilter, root, /usr/bin/python2.6, -9