Issue based on post on GG

Sentry found a couple new memory leaks today, introduced here:
https://github.com/mongodb/mongo/commit/7c8cfd9
I know it's test code, but someone may be interested in cleaning it up anyway. In dbtests/perftests.cpp, around line 180:
DBClientConnection *c = new DBClientConnection(false, 0, 10);
string err;
if( c->connect("mongo05.10gen.cust.cbici.net", err) ) {
if( !c->auth("perf", "perf", pwd, err) )

{ cout << "info: authentication with stats db failed: " << err << endl; // XXX: c leaked on this path assert(false); }

conn = c;
}
else

{ cout << err << " (to log perfstats)" << endl; // XXX: c leaked on this path }

I've noted the two locations where the connection 'c' is leaked in the above code (goes out of scope without being reassigned or deleted). Again, not a big deal if these are short-lived tests, but worth fixing if the tests are resource intensive.