$v_nginx_cache was set to no instead empty

web/templates/admin/edit_web.html

@@ -382,7 +382,7 @@
                                         <?php if($_SESSION['WEB_SYSTEM'] == 'nginx'){?>
                                         <tr>
                                             <td class="vst-text">
-                                                <label><input type="checkbox" size="20" class="vst-checkbox" name="v_nginx_cache_check" <?php if (!empty($v_nginx_cache)) echo "checked=yes" ?> onclick="javascript:elementHideShow('v_nginx_duration');"><?php print _('Enable FastCGI Cache'); ?> <a href="https://docs.hestiacp.com/admin_docs/nginx_caching.html" target="_blank"><i class="fas fa-question-circle"></i></a></label>
+                                                <label><input type="checkbox" size="20" class="vst-checkbox" name="v_nginx_cache_check" <?php if ($v_nginx_cache == 'yes') echo "checked=yes" ?> onclick="javascript:elementHideShow('v_nginx_duration');"><?php print _('Enable FastCGI Cache'); ?> <a href="https://docs.hestiacp.com/admin_docs/nginx_caching.html" target="_blank"><i class="fas fa-question-circle"></i></a></label>
                                             </td>
                                         </tr>
                                         <tr>