Update net.cpp
Update net.cpp

We previously would block waiting for a CSemaphoreGrant in
ThreadOpenAddedConnections, when we did not need to. This would
block as the posts in CConnman shutdown were both to the wrong
semaphore and in the wrong location.
LIMXTEC/BitCore,LIMXTEC/BitCore,LIMXTEC/BitCore,LIMXTEC/BitCore,LIMXTEC/BitCore,LIMXTEC/BitCore