the BGP multipath code was developed against a pre-f6f434b Quagga where
bgp_attr_unintern and ecommunity_free took single-star pointers.  They
now take double-star pointers.

  * bgpd/bgp_mpath.c: fix up bgp_attr_unintern & ecommunity_free calls.

Signed-off-by: David Lamparter <[email protected]>