Don't return invalid size from wxDir::GetTotalSize() for empty dirs.

wxDirTraverserSumSize::GetTotalSize() may, and will, return 0 for empty
directories, this is not an error and so don't treat it as such.

Closes #11937.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@64018 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/dircmn.cpp

@@ -347,8 +347,7 @@ wxULongLong wxDir::GetTotalSize(const wxString &dirname, wxArrayString *filesSki
         return wxInvalidSize;
 
     wxDirTraverserSumSize traverser;
-    if (dir.Traverse(traverser) == (size_t)-1 ||
-        traverser.GetTotalSize() == 0)
+    if (dir.Traverse(traverser) == (size_t)-1 )
         return wxInvalidSize;
 
     if (filesSkipped)