Refactor ConnectionReaperCallback

The ConnectionReaperCallback is only used by the TapConnMap
so we don't need to try to notify the UprConnMap.

Change-Id: Id10c64ac78013ae66690325b93e6dc0d157bd34e
Reviewed-on: http://review.couchbase.org/34203
Reviewed-by: Michael Wiederhold <mike@couchbase.com>
Tested-by: Michael Wiederhold <mike@couchbase.com>