fruity: Expect networked device to respond quickly

When connecting to its pairing service, it should be reasonable to
assume that the TCP connection set up completes within two seconds.

This improves the UX when a device has gone to sleep, and its mDNS
records haven't yet timed out.

src/fruity/device-monitor.vala

@@ -1808,6 +1808,8 @@ namespace Frida.Fruity {
 		private TunnelConnection? tunnel_connection;
 		private DiscoveryService? _discovery_service;
 
+		private const uint PAIRING_CONNECTION_TIMEOUT = 2000;
+
 		public PortableNetworkTunnel (InetSocketAddress endpoint, InetSocketAddress interface_address, PairingStore store) {
 			Object (
 				endpoint: endpoint,
@@ -1819,7 +1821,8 @@ namespace Frida.Fruity {
 		public async void open (Cancellable? cancellable) throws Error, IOError {
 			var netstack = new SystemNetworkStack (interface_address.get_address (), interface_address.scope_id);
 
-			var pairing_connection = yield netstack.open_tcp_connection (endpoint, cancellable);
+			var pairing_connection = yield netstack.open_tcp_connection_with_timeout (endpoint, PAIRING_CONNECTION_TIMEOUT,
+				cancellable);
 			var pairing_transport = new PlainPairingTransport (pairing_connection);
 			var pairing_service = yield PairingService.open (pairing_transport, pairing_store, cancellable);