Re #269 - Fix env var comment name

changedetectionio/templates/settings.html

@@ -36,7 +36,7 @@
                         {{ render_field(form.base_url, placeholder="http://yoursite.com:5000/",
                         class="m-d") }}
                         <span class="pure-form-message-inline">
-                            Base URL used for the {base_url} token in notifications, default value is the ENV var 'base_url',
+                            Base URL used for the {base_url} token in notifications, default value is the ENV var 'BASE_URL',
                             <a href="https://github.com/dgtlmoon/changedetection.io/wiki/Configurable-BASE_URL-setting">read more here</a>.
                         </span>
                     </div>