fix(tsconnect): drop nethttpomithttp2 build tag

After 1d93bdce2 ("control/controlclient: remove x/net/http2, use
net/http"), the noise control client uses net/http's Transport with
Protocols.SetUnencryptedHTTP2(true). The nethttpomithttp2 build tag
strips the bundled HTTP/2 implementation from net/http, so at runtime
the control client fails the first register request with "http:
Transport does not support unencrypted HTTP/2" and the wasm never
connects.

Drop the tag so the bundled HTTP/2 ships in the wasm binary.

cmd/tsconnect/common.go

@@ -228,7 +228,7 @@ func buildWasm(dev bool) ([]byte, error) {
 	// to fail for unclosed files.
 	defer outputFile.Close()
 
-	args := []string{"build", "-tags", "tailscale_go,osusergo,netgo,nethttpomithttp2,omitidna,omitpemdecrypt"}
+	args := []string{"build", "-tags", "tailscale_go,osusergo,netgo,omitidna,omitpemdecrypt"}
 	if !dev {
 		if *devControl != "" {
 			return nil, fmt.Errorf("Development control URL can only be used in dev mode.")