safesocket: remove the now unused WindowsLocalPort

Also drop the port param from safesocket.Listen. #cleanup

Signed-off-by: Maisem Ali <maisem@tailscale.com>

cmd/tsconnect/wasm/wasm_js.go

@@ -301,7 +301,7 @@ func (i *jsIPN) run(jsCallbacks js.Value) {
 	}()
 
 	go func() {
-		ln, _, err := safesocket.Listen("", 0)
+		ln, err := safesocket.Listen("")
 		if err != nil {
 			log.Fatalf("safesocket.Listen: %v", err)
 		}