Revert "Fix off by 1 error in wxGenericListCtrl::HitTest()."

Revert r73563, this breaks the selection in the control apparently.

See #15063.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@73596 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/listctrl.cpp

@@ -4144,10 +4144,6 @@ long wxListMainWindow::HitTest( int x, int y, int &flags ) const
 
     if ( InReportView() )
     {
-        // Account for the header height if it's present.
-        if ( HasHeader() )
-            y -= GetListCtrl()->m_headerWin->GetSize().y + 1;
-
         size_t current = y / GetLineHeight();
         if ( current < count )
         {