Report deletion should be logged

[AndyF]

Surprised really but there is no moderator log entry generated for when a moderator or admin deletes entries from the Report Centre.

Verified on two boards so its not a bug as far as I can tell. :)

I think it would be a good idea to log this really as well as slightly destructive it also (imo) falls into the category of being a moderator "action" too so I feel it should be logged.