Remove useless wxABI_VERSION checks in sources

They are only meaningful for headers, not when compiling the library
itself.

src/generic/listctrl.cpp

@@ -5117,12 +5117,10 @@ wxTextCtrl *wxGenericListCtrl::EditLabel(long item,
     return m_mainWin->EditLabel( item, textControlClass );
 }
 
-#if wxABI_VERSION >= 30002
 bool wxGenericListCtrl::EndEditLabel(bool cancel)
 {
     return m_mainWin->EndEditLabel(cancel);
 }
-#endif
 
 wxTextCtrl *wxGenericListCtrl::GetEditControl() const
 {

src/osx/carbon/listctrl_mac.cpp

@@ -553,7 +553,6 @@ void wxListCtrl::OnDblClick(wxMouseEvent& event)
     event.Skip();
 }
 
-#if wxABI_VERSION >= 20801
 void wxListCtrl::OnRightDown(wxMouseEvent& event)
 {
     if (m_dbImpl)
@@ -636,7 +635,6 @@ void wxListCtrl::OnChar(wxKeyEvent& event)
     }
     event.Skip();
 }
-#endif
 
 bool wxListCtrl::Create(wxWindow *parent,
                         wxWindowID id,