Ensure that a dropped network connection does not leave references to the UpgradeProcessor associated with the connection in memory.

The physical mobile connection can die at random times. When the connection goes down the instance of org.apache.coyote.http11.upgrade.NioProcessor is not removed from the connections HashMap in class

https://bz.apache.org/bugzilla/show_bug.cgi?id=57546
http://svn.apache.org/r1658737
http://svn.apache.org/r1658794