fix: add non allowed domain translation

- Was added in 2559c80 and accidentally
removed in 5a16c9d.
- Reworded for clarity.
- Resolves go-gitea#6661

Author: Gusted

options/locale/locale_en-US.ini

@@ -644,6 +644,7 @@ team_name_been_taken = The team name is already taken.
 team_no_units_error = Allow access to at least one repository section.
 email_been_used = The email address is already used.
 email_invalid = The email address is invalid.
+email_domain_is_not_allowed = The domain of the user's email address <b>%s</b> conflicts with EMAIL_DOMAIN_ALLOWLIST or EMAIL_DOMAIN_BLOCKLIST. Make sure you have set the email address correctly.
 openid_been_used = The OpenID address "%s" is already used.
 username_password_incorrect = Username or password is incorrect.
 password_complexity = Password does not pass complexity requirements: