Fix closing a report where the reporter is deactivated

Fixes #133 (closed)

Previously reports from deactivated users were being filtered out, if the user was deactivated before the report was closed.

Now reports need to be closed explicitly, regardless of whether you deactivate the user.

Only problem is, the bug in #133 (closed) prevented closing a report by a deactivated user. The reason? ...filtering out deactivated users.

So the fix is to pass an empty list [] to the Activity.get_by_id/2 function, making it NOT filter deactivated accounts for this action.