controlpanel.cpp: Increase verbosity of successful "Disconnect" command

This modifies line 897 to have more verbosity on the output for a successful execution of the "Disconnect" command, which will allow for the output to say what network was force-disconnected on what user.

This is a repaired version of pull request #352 which I closed after a FTBFS which I did not realize.
Merge pull request #353 from TheLordOfTime/patch-1

controlpanel.cpp: Increase verbosity of successful "Disconnect" command