drop unneeded forward declare

Change-Id: Ib9a7d484cb93c0dbf6a13b540895e0e5d5c00d49
Reviewed-on: https://gerrit.libreoffice.org/72202Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

sc/source/ui/inc/tabvwsh.hxx

@@ -38,7 +38,6 @@
 class SdrOle2Obj;
 class SfxBindings;
 class SfxChildWindow;
-class SfxModelessDialog;
 class SvxNumberInfoItem;
 struct SfxChildWinInfo;