corrected build fix, new code does work with GTK+ < 2.10

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@58822 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/taskbar.cpp

@@ -12,7 +12,7 @@
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
-#if wxUSE_TASKBARICON && defined(__WXGTK210__)
+#if wxUSE_TASKBARICON
 
 #include "wx/taskbar.h"
 
@@ -25,6 +25,10 @@
 #include "eggtrayicon.h"
 #include <gtk/gtk.h>
 
+#if !GTK_CHECK_VERSION(2,10,0)
+    typedef struct _GtkStatusIcon GtkStatusIcon;
+#endif
+
 class wxTaskBarIcon::Private
 {
 public: