.csv attachement is not processed

**Description**
If message has .CSV attachement, method getAttachements() don't return it

**To Reproduce**
Get message with .csv attachement or with multiple attachements, with one .csv and try to get them all.

**Expected behavior**
.csv attachement shold be processed

**Screenshots**
N/A

**Desktop / Server (please complete the following information):**
 - OS: Win 10
- PHP: 7.2

