invalid attachment link

When a notification arrives in Rocket Chat, the link for the attachment is generated incorrectly, the file name in the link is duplicated, respectively, the link is not working.

```
http://redmine.mydomen.com/attachments/310/BRN3C2AF4A38E98_005212.pdf%7CBRN3C2AF4A38E98_005212.pdf
```