Remove unused forward declaration

src/messagedisplay.h

@@ -11,7 +11,6 @@
 #include "messagedisplayhelper.h"
 #include "kalarmcalendar/kaevent.h"
 
-class KConfigGroup;
 class DeferAlarmDlg;
 class EventId;
 class MessageDisplayHelper;

src/messagewindow.h

@@ -20,7 +20,6 @@ class PushButton;
 class MessageText;
 class QCheckBox;
 class QLabel;
-class EditAlarmDlg;
 
 using namespace KAlarmCal;