Remove wx/arrstr.h from headers

src/import/Import.h

@@ -15,12 +15,12 @@
 #include "ImportForwards.h"
 #include "audacity/Types.h"
 #include <vector>
-#include <wx/arrstr.h>
 #include <wx/listbox.h>
 #include <wx/tokenzr.h>
 
 #include "../widgets/wxPanelWrapper.h"
 
+class wxArrayString;
 class Tags;
 class TrackFactory;
 class Track;

src/import/ImportPlugin.h

@@ -66,6 +66,7 @@ but little else.
 
 #include "ImportRaw.h" // defines TrackHolders
 
+class wxArrayString;
 class TrackFactory;
 class Track;
 class Tags;