Watchlist: Show 'Watchlist's changesets' button only if users are added

[danieldegroot2]

What feature would you like to see added?

Show 'Watchlist's changesets' button only if users are added.

Currently it is shown also with 0 users, which of course results in 0 changes and is redundant/unusable.

Why would this be useful to you or other users?

Allow users to see watched changesets, but only when they have specified users to watch.

Currently, it is possibly to view empty list, which is not useful.