Fix setting the label for already existing menu items with bitmaps in wxMSW.

Do update the label at Windows level if we don't use MF_OWNERDRAW style,
checking for IsOwnerDrawn() is wrong because the flag it tests may be set even
if the item is not really owner drawn from Windows point of view.

This is a mess and setting the bitmap for the existing items is still broken,
but at least setting the label works now.

See #9388.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76042 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775