add AdvertiseAddrWan to TestMergeConfig and use different values for Addr values in b than in a

command/agent/config_test.go

@@ -1070,12 +1070,13 @@ func TestMergeConfig(t *testing.T) {
 			MaxStale:       30 * time.Second,
 			EnableTruncate: true,
 		},
-		Domain:        "other",
-		LogLevel:      "info",
-		NodeName:      "baz",
-		ClientAddr:    "127.0.0.1",
-		BindAddr:      "127.0.0.1",
-		AdvertiseAddr: "127.0.0.1",
+		Domain:           "other",
+		LogLevel:         "info",
+		NodeName:         "baz",
+		ClientAddr:       "127.0.0.2",
+		BindAddr:         "127.0.0.2",
+		AdvertiseAddr:    "127.0.0.2",
+		AdvertiseAddrWan: "127.0.0.2",
 		Ports: PortConfig{
 			DNS:     1,
 			HTTP:    2,