bgpd: Avoid double aspath_dup() for confederation when remote-as != AS_SPECIFIED

bgpd: Avoid double aspath_dup() for confederation when remote-as != AS_SPECIFIED

Just was blind when not seing it's already dup'ed above:

```	if (peer->sort == BGP_PEER_EBGP
	    && (!CHECK_FLAG(peer->af_flags[afi][safi],
			    PEER_FLAG_AS_PATH_UNCHANGED)
		|| attr->aspath->segments == NULL)
	    && (!CHECK_FLAG(peer->af_flags[afi][safi],
			    PEER_FLAG_RSERVER_CLIENT))) {
		aspath = aspath_dup(attr->aspath); <<<<<<<<<<<<<<<
```

Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>