bgpd: update AS value of a hidden bgp instance

'import vrf CUSTOM' could define a hidden bgp instance with
the default AS_UNSPECIFIED (i.e. = 1) value.
When a
	router bgp AS vrf CUSTOM
gets configured later on, replace this AS_UNSPECIFIED setting
with a requested value.

Signed-off-by: Alexander Skorichenko <askorichenko@netgate.com>

bgpd/bgpd.c

@@ -3401,18 +3401,20 @@ static struct bgp *bgp_create(as_t *as, const char *name,
 	afi_t afi;
 	safi_t safi;
 
-	if (hidden) {
+	if (hidden)
 		bgp = bgp_old;
-		goto peer_init;
-	}
+	else
+		bgp = XCALLOC(MTYPE_BGP, sizeof(struct bgp));
 
-	bgp = XCALLOC(MTYPE_BGP, sizeof(struct bgp));
 	bgp->as = *as;
 	if (as_pretty)
 		bgp->as_pretty = XSTRDUP(MTYPE_BGP_NAME, as_pretty);
 	else
 		bgp->as_pretty = XSTRDUP(MTYPE_BGP_NAME, asn_asn2asplain(*as));
 
+	if (hidden)
+		goto peer_init;
+
 	if (asnotation != ASNOTATION_UNDEFINED) {
 		bgp->asnotation = asnotation;
 		SET_FLAG(bgp->config, BGP_CONFIG_ASNOTATION);