MailWindow: Trim folder name when previewing email docs

Elwig/Windows/MailWindow.xaml.cs

@@ -541,7 +541,7 @@ namespace Elwig.Windows {
                 PrintDocument?.SaveTo($"{d.FolderName}/Print.pdf");
                 if (EmailDocuments != null) {
                     foreach (var (m, docs) in EmailDocuments) {
-                        var folder = $"{d.FolderName}/E-Mail/{m.AdministrativeName}";
+                        var folder = $"{d.FolderName}/E-Mail/{m.AdministrativeName.Trim()}";
                         Directory.CreateDirectory(folder);
                         foreach (var item in docs.Select((d, i) => new { Index = i, Doc = d })) {
                             var doc = item.Doc;