False notification of a mention

### Step 1: Please describe your environment

* ZeroNet version: v3840

### Step 2: Describe the problem:

A reply to user rxxxxx notifies user 'r'. Parsing issue?

#### Observed Results:

Screenshot: [https://i.imgur.com/Bhqej7r.png](https://i.imgur.com/Bhqej7r.png
)

Start by reproducing the false notification on ZeroNet v3840 using a reply to user rxxxxx, then trace the mention parsing and notification entry points. Done means the reply notifies only the intended user rather than user 'r'; the issue provides no file or test names.

Rédigé par le modèle d'indexation à partir du texte de l'issue.