Fix invalid edit preview path

This commit fixes an invalid edit preview path, when editing a post you would get an error:
```
Warning: require(/home/craig/public_html/forum/style/Core/templates/views/views/edit-preview.tpl.php): failed to open stream: No such file or directory in /home/craig/public_html/forum/edit.php on line 158
 
Fatal error: require(): Failed opening required '/home/craig/public_html/forum/style/Core/templates/views/views/edit-preview.tpl.php' (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/craig/public_html/forum/edit.php on line 158
```