make leak warning take number of connections info consideration WAS: I would like a way to set the threshold for the memory leak warning message

We get a lot of messages like this:
Wed Oct 12 09:18:45 [conn1158] warning: virtual size (447986MB) - mapped size (434286MB) is large. could indicate a memory leak

It looks like this is triggered whenever someone does db.serverStatus(), if virtual - mapped >5000 MB.

I would like this to be a configurable value, rather than a fixed size of 5000 MB. Ideally, the threshold could be changed without restarting the server.