[BUG] Installations from scratch don't send the alerts email

[c3s4rfred]

Describe the bug
When you perform a fresh installation, the first alerts to arrive aren't sent by email, even if the email configuration settings are fine, because the method in the backend checks the time.now(), so the first alert's time is behind of the current time, so the email won't be sent.

To Reproduce
Steps to reproduce the behavior:

1. Perform installation from scratch
2. Generate alerts
3. The email is not sent

Expected behavior
Register a day back to check the first time.

Environment

• UTMStack RC 10.2.3