Fixes a race condition in the Dispatcher, when an entry in the dispatcher was removed during the iteration in the dispatcher loop.
Fixes a race condition in the Dispatcher, when an entry in the dispatcher was removed during the iteration in the dispatcher loop.

bakerstu/openmrn,bakerstu/openmrn,bakerstu/openmrn,bakerstu/openmrn,bakerstu/openmrn,bakerstu/openmrn