Support IPv4 HTTP public gateway entries

backend/internal/nginxgateway/gateway_test.go

@@ -12,6 +12,7 @@ func TestParseManagedEntry(t *testing.T) {
 		{Domain: "vpn.example.com", Scheme: "https", Port: 443},
 		{Domain: "vpn.example.com", Scheme: "https", Port: 8443},
 		{Domain: "vpn.example.com", Scheme: "http", Port: 28080},
+		{Domain: "121.4.111.208", Scheme: "http", Port: 28080},
 	} {
 		httpSite, httpsSite, err := nginxconfig.RenderWithOptions(want, nil, 0)
 		if err != nil {