OicClient: Remove handle when PRESENCE_TRIGGER_DELETE event is received

[nagineni]

Delete the handle from the list when the presence is disabled and device has been deleted.

[nagineni]

@gabrielschulhof

[gabrielschulhof]

I think a better way would be to OCCancel() not during OC_PRESENCE_TRIGGER_DELETE, but during device addition, because there's a case where you device.disablePresence(), but you don't terminate the process right thereafter. That's the scenario being explored by the failing test. I'll make a test where the server is being restarted, to make sure you get the delete event the second time around as well.

[gabrielschulhof]

Actually, it's much simpler than that. All you have to do is unconditionally re-issue the open-ended presence request upon rediscovery of a given server, because _openEndedRequest() does the OCCancel() for you. IOW, you just remove the if-statement from around the _openEndedRequest() for presence tracking.

[nagineni]

Initially I tested by removing that if condition to solve the issue, but I was not fully sure whether it's okay to remove it or not. Please merge the commit, if you are sure that it will not introduce any regression by removing it.

[gabrielschulhof]

OK. I'm relying on the tests to spot regressions, and they're all passing, so I'm assuming that we have no regressions.

[nagineni]

Great! :)