bgpd: traffic rate value is ignored for searching bpa

bgpd: traffic rate value is ignored for searching bpa

There are cases where a redirect IP or redirect VRF stops the ecom
parsing, then ignores a subsequent rate value, letting passed value to
0. Consequently, a new table identifier may be elected, despite the
routing procedure is the same. This fix ignores the rate value in bpa
list.

Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>