Remove WM_SYSKEYDOWN handling at component level, in consistency with other components (ListView,...)
Early embodiement of the fix proposed to WineHQ:
https://bugs.winehq.org/show_bug.cgi?id=49097 in order to remove functional limitation in ReactOS.
Fixes regressions CORE-17020 and CORE-12203 that were once introduced
by SVN r72320 == git
297e33f2286ef0ec210108562cd0e87ad02d036b
during COMCTL32 WineSync 1.9.16 CORE-11866
Fix picked from 0.4.15-dev-191-g
295ba62820a1cdad86ebadc4d8a2d20c799a08d4
return TREEVIEW_HScroll(infoPtr, wParam);
case WM_KEYDOWN:
+#ifndef __REACTOS__
case WM_SYSKEYDOWN:
+#endif
return TREEVIEW_KeyDown(infoPtr, wParam);
case WM_KILLFOCUS: