PHP 8.1+ compatibility for NFW with WP multisite

When running NFW in Full WAF mode with a multisite instance of WordPress, the existing code for querying the options table no longer works with PHP 8.1+, as querying a non-existent table yields an exception in PHP 8.1+.

Please consider replacing the nested conditionals with try/catch to ensure that the exception is handled:

lib/firewall.php

                    try {
                            $nfw_['result'] = @$nfw_['mysqli']->query('SELECT * FROM ' . $nfw_['mysqli']->real_escape_string($nfw_['table_prefix']) . "options WHERE option_name = 'nfw_options'");
                    }
                    catch (Exception $e){
                            // Maybe this is an old multisite install where the main site
                            // options table is named 'wp_1_options' instead of 'wp_options'
                            try {
                                    $nfw_['result'] = @$nfw_['mysqli']->query('SELECT * FROM ' . $nfw_['mysqli']->real_escape_string($nfw_['table_prefix']) . "1_options WHERE option_name = 'nfw_options'");
                                    // Change the table prefix to match 'wp_1_options'
                                    $nfw_['table_prefix'] = "{$nfw_['table_prefix']}1_";
                            }
                            catch (Exception $e){
                                    return 5;
                            }
                    }