fix extension installation broken by #9518

    return url

def install_extension_from_url(dirname, branch_name, url):

def install_extension_from_url(dirname, url, branch_name=None):

    check_access()

    assert url, 'No URL specified'

    try:

        shutil.rmtree(tmpdir, True)

        if branch_name == '':

        if not branch_name:

            # if no branch is specified, use the default branch

            with git.Repo.clone_from(url, tmpdir) as repo:

                repo.remote().fetch()

                install_button.click(

                    fn=modules.ui.wrap_gradio_call(install_extension_from_url, extra_outputs=[gr.update()]),

                    inputs=[install_dirname, install_branch, install_url],

                    inputs=[install_dirname, install_url, install_branch],

                    outputs=[extensions_table, install_result],

                )