swarm: various fixes

This patch fixes current unitTest
+ Fix testCreateConversationWithMessagesThenAddDevice messageReceived
flag
+ Remove useless sleep in tests
+ in ut_conversation fix messageReceived flag
+ lock convInfo and convRequests to avoid invalid write operations
+ fix pending callbacks if connected via a DHT request
+ remove useless log

Change-Id: If53ecf0c064e9c1424c11a4af1e13d31294e6be9