Changes to a number of dialogs so that the NVDA screen reader can read the titles. Missed these in my last patch. The accessibility name of the dialog is set to the title.

src/export/ExportFFmpeg.cpp

@@ -904,6 +904,7 @@ void ExportFFmpeg::SetMetadata(Tags *tags, const char *name, const wxChar *tag)
 int ExportFFmpeg::AskResample(int bitrate, int rate, int lowrate, int highrate, const int *sampRates)
 {
    wxDialog d(NULL, wxID_ANY, wxString(_("Invalid sample rate")));
+   d.SetName(d.GetTitle());
    wxChoice *choice;
    ShuttleGui S(&d, eIsCreating);
    wxString text;