don't include GNOME FS header if we don't use it (and might not have it at all)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@38800 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/unix/mimetype.cpp

@@ -58,8 +58,10 @@
 
 #include "wx/unix/mimetype.h"
 
-// Not GUI dependent
-#include "wx/gtk/gnome/gvfs.h"
+#if wxUSE_LIBGNOMEVFS
+    // Not GUI dependent
+    #include "wx/gtk/gnome/gvfs.h"
+#endif
 
 // other standard headers
 #include <ctype.h>