[OJS] User profile notification page configurations

Hello everyone,

Description of issue or problem I’m having:
While “fixing” by author’s request the notifications on their page, I came across the following issue. Not such big a deal, but not the ideal for the situation

The events titles are loading a variable that doesn’t exist yet, as they are related to a submssion, but this is the notifications configuration page.

Steps I took leading up to the issue:
Entering user profile > notifications

What I tried to resolve the issue:
Fixed lib/pkp/locale/pt_BR/common.po to a more generic content, without the variable. There may be a need to add specific locale keys for this page, as these are e-mail related.

Application Version - e.g., OJS 3.1.2:

Additional information, such as screenshots and error log messages if applicable: