Add variable for controlling service.ENABLE_NOTIFY_MAIL and wire it…

… to `mailer.ENABLED` by default

Without `service.ENABLE_NOTIFY_MAIL` being enabled, the mailer (if enabled) is
only used for important transactional emails, but not for sending
notifications to people about stuff they're watching.

This is not very useful, so we're changing the defaults. If a mailer is
configured, it shall be used for notification emails by default.

defaults/main.yml

@@ -39,6 +39,12 @@ gitea_config_database_name: gitea
 gitea_config_database_username: ''
 gitea_config_database_password: ''
 
+# Enable this to send e-mail to watchers of a repository when something happens, like creating issues. Requires Mailer to be enabled.
+# See: https://docs.gitea.com/administration/config-cheat-sheet#service-service
+#
+# We enable this by default if the mailer is enabled, because it makes sense use it for more than just transactional emails.
+gitea_config_service_enable_notify_email: "{{ gitea_config_mailer_enabled }}"
+
 gitea_config_mailer_enabled: false
 gitea_config_mailer_from: ''
 gitea_config_mailer_protocol: ''

templates/env.j2

@@ -10,6 +10,8 @@ GITEA__database__PASSWD={{ gitea_config_database_password }}
 
 GITEA____RUN_USER={{ gitea_config_run_user }}
 
+GITEA__service__ENABLE_NOTIFY_MAIL={{ gitea_config_service_enable_notify_email }}
+
 {% if gitea_config_mailer_enabled %}
 GITEA__mailer__ENABLED={{ gitea_config_mailer_enabled }}
 GITEA__mailer__FROM={{ gitea_config_mailer_from }}