Index: src/wp-admin/includes/class-wp-upgrader-skins.php
===================================================================
--- src/wp-admin/includes/class-wp-upgrader-skins.php	(revision 33517)
+++ src/wp-admin/includes/class-wp-upgrader-skins.php	(working copy)
@@ -660,7 +660,7 @@
 		$install_actions = array();
 
 		if ( current_user_can( 'edit_theme_options' ) && current_user_can( 'customize' ) ) {
-			$install_actions['preview'] .= '<a href="' . wp_customize_url( $stylesheet ) . '" class="hide-if-no-customize load-customize"><span aria-hidden="true">' . __( 'Live Preview' ) . '</span><span class="screen-reader-text">' . sprintf( __( 'Live Preview &#8220;%s&#8221;' ), $name ) . '</span></a>';
+			$install_actions['preview'] = '<a href="' . wp_customize_url( $stylesheet ) . '" class="hide-if-no-customize load-customize"><span aria-hidden="true">' . __( 'Live Preview' ) . '</span><span class="screen-reader-text">' . sprintf( __( 'Live Preview &#8220;%s&#8221;' ), $name ) . '</span></a>';
 		}
 		$install_actions['activate'] = '<a href="' . esc_url( $activate_link ) . '" class="activatelink"><span aria-hidden="true">' . __( 'Activate' ) . '</span><span class="screen-reader-text">' . sprintf( __( 'Activate &#8220;%s&#8221;' ), $name ) . '</span></a>';