textile: Fix textile_version fatal error, update syntax link

Author: onli

plugins/serendipity_event_textile/ChangeLog

@@ -1,4 +1,8 @@
-2.0.1: One PHP 8 warning fixed
+2.0.1:
+     * Fix one PHP 8 warning
+     * Fix error when opening entries in blogs that had the prior version installed
+     * Link to textile-lang.com to explain the syntax below the comment form, instead of defunct
+       sites
 
 2.0: Remove old textile parsers and switch to netcarver/textile v4.1.3
      This will improve compatibility with current PHP version (8.x).

plugins/serendipity_event_textile/serendipity_event_textile.php

@@ -112,6 +112,9 @@ function introspect_config_item($name, &$propbag)
                 $propbag->add('description', PLUGIN_EVENT_TEXTILE_UNESCAPE_DESC);
                 $propbag->add('default',     'false');
                 break;
+            case 'textile_version':
+                // For backwards compatibility, otherwise the constant call below will die
+                break;
 
             default:
                 $propbag->add('type',        'boolean');
@@ -200,11 +203,8 @@ function event_hook($event, &$bag, &$eventData, $addData = null)
                     break;
 
                 case 'frontend_comment':
-                    if (serendipity_db_bool($this->get_config('COMMENT', 'true'))) {
-                        $url = $this->get_config('textile_version') == 1
-                                   ? 'http://www.textism.com/tools/textile/'
-                                   : 'http://txstyle.org/article/43/a-short-introduction';
-                        echo '<div class="serendipity_commentDirection serendipity_comment_textile">' . sprintf(PLUGIN_EVENT_TEXTILE_TRANSFORM, $url) . '</div>';
+                    if (serendipity_db_bool($this->get_config('COMMENT', 'true'))) {;
+                        echo '<div class="serendipity_commentDirection serendipity_comment_textile">' . sprintf(PLUGIN_EVENT_TEXTILE_TRANSFORM, 'https://textile-lang.com/') . '</div>';
                     }
                     break;