ns: TC_sns_bss_change_weight_timeout: fix expected SNS_SIZE PDU

Allow to work with IPv4 and IPv6 endpoints and only expected known required
fields (e.g. NSEI and rst_flag).

Related: OS#5036
Change-Id: I60f669d7c8838d460a14c6604c4375a8d47f5149
diff --git a/ns/NS_Tests.ttcn b/ns/NS_Tests.ttcn
index 1715b2e..29e5669 100644
--- a/ns/NS_Tests.ttcn
+++ b/ns/NS_Tests.ttcn
@@ -517,8 +517,16 @@
 	[] as_rx_alive_tx_ack();
 	}
 
-	f_ns_exp(tr_SNS_SIZE(g_nsconfig.nsei, rst_flag := true, max_nsvcs := 8,
-				   num_v4 := 4, num_v6 := omit), 0);
+	if (nsvc_cfg.provider.ip.address_family == AF_INET) {
+		/* expect one single SNS-SIZE with RESET flag; 4x v4 EP; no v6 EP */
+		rx := f_ns_exp(tr_SNS_SIZE(g_nsconfig.nsei, rst_flag := true, max_nsvcs := ?,
+					   num_v4 := ?, num_v6 := omit), 0);
+	} else {
+		/* expect one single SNS-SIZE with RESET flag; no v4 EP; 4x v6 EP */
+		rx := f_ns_exp(tr_SNS_SIZE(g_nsconfig.nsei, rst_flag := true, max_nsvcs := ?,
+					   num_v4 := omit, num_v6 := ?), 0);
+	}
+
 	setverdict(pass);
 	f_clean_ns_codec();
 }