restriction of contents of notifications (both, subject and body)

[xyanipheia]

In #8294 GPG encoded notifications were mentioned. An easy workaround is to restrict the content of notifications. In this case no critical content is sent to the recipients, only a ticket number and the project link. Of course, encrypted notification is more preferable, but maybe this approach may be implemented earlier than milestone 2.0 für #8294? This approach allows to use TRAC in restricted environments if additionally:

• the server is protected (https with client certificates, …
• the project names are chosen to be simple, e.g. only project-numbers