Correctly acknowledge the size on DCC RESUME
Correctly acknowledge the size on DCC RESUME

We usually send the received data on the socket, but on the case of a
resume we ought to start acknowledging the received data plus the
starting offset. This is not on the protocol but match what the server
expect on practice.

glguy/irc-core,dolio/irc-core,dolio/irc-core,glguy/irc-core,dolio/irc-core,glguy/irc-core