Remove some outdated comment

Since b359f968 / r2171 this comment is outdated, but someone (*cough*) forgot to
remove it back then.

Signed-off-by: Uli Schlachter <psychon@znc.in>

ClientCommand.cpp

@@ -297,9 +297,6 @@ void CClient::UserCommand(CString& sLine) {
 		m_pUser->CheckIRCConnect();
 		return;
 	} else if (sCommand.Equals("DISCONNECT")) {
-		// GetIRCSock() is only set after the low level connection
-		// to the IRC server was established. Before this we can
-		// only find the IRC socket by its name.
 		if (GetIRCSock()) {
 			CString sQuitMsg = sLine.Token(1, true);
 			GetIRCSock()->Quit(sQuitMsg);