Missing <wx/sizer.h> include

Without it build on my Windows host fails

lib-src/FileDialog/win/FileDialogPrivate.cpp

@@ -44,6 +44,7 @@
 #include <wx/dynlib.h>
 #include <wx/filename.h>
 #include <wx/scopeguard.h>
+#include <wx/sizer.h>
 #include <wx/tokenzr.h>
 #include <wx/modalhook.h>
 
@@ -1197,4 +1198,4 @@ bool FileDialog::Disabler::IsChild(const wxDialog *dialog) const
    }
 
    return false;
-}
+}