This is a classic XY problem question, the original problem you face is:

 > "How do I prevent a client from disabling the woocommerce plugin"

For which mu-plugins was your solution, to which you are now asking for a fix for your solution, aka a fix for a fix, never a good sign.

So addressing your original problem we have:

If WooCommerce is disabled, warn the user that it has been disabled, fail gracefully, and put links to the reactivation button here there and everywhere. The client should very quickly get the message that what they did will break the site


Disable the disable link, e.g. for the facebook open graph plugin:

    test

    add_filter( 'plugin_action_links', 'disable_plugin_deactivation', 10, 4 );
    function disable_plugin_deactivation( $actions, $plugin_file, $plugin_data, $context ) {
    	// Remove edit link for all
    	if ( array_key_exists( 'edit', $actions ) )
    		unset( $actions['edit'] );
    	// Remove deactivate link for crucial plugins
    	if ( array_key_exists( 'deactivate', $actions ) && in_array( $plugin_file, array(
    		'facebook-open-graph-meta-in-wordpress/fbogmeta.php'
    	)))
    		unset( $actions['deactivate'] );
    	return $actions;
    }

Or best of all, remove the plugins page entirely.