Fix matching context of our most important bubble : Alternatives to Amazon books

[MaartenLMEM]

Bubble n° 2019 is no more displayed since beginning of october 2021.
Cause : Amazon website probably changed its product page structure.

To do :

1. Fix xpath - Grégoire (or Jalil)
2. Make an rescue regex in case it is down - Maarten

Link to the notice : https://notices.lmem.net/admin/?action=edit&entity=Notice&menuIndex=&submenuIndex=&query=2019&sortField=id&sortDirection=DESC&page=1&referer=%252Fadmin%252F%253Faction%253Dsearch%2526entity%253DNotice%2526menuIndex%253D%2526submenuIndex%253D%2526query%253D2019%2526sortField%253Did%2526sortDirection%253DDESC%2526page%253D1&id=2019