fix: invalid folder path for SQL export cannot be created if it contains a duplicated path delimiter

Custom output dir may already have a trailing path delimiter, only add when not
Broken in 2e290f1

Refs #2558

Author: ansgarbecker

source/tabletools.pas

@@ -1848,7 +1848,7 @@ procedure TfrmTableTools.DoExport(DBObj: TDBObject);
 
   if ToDir then begin
     FreeAndNil(ExportStream);
-    DbDir := GetOutputFilename(comboExportOutputTarget.Text, DBObj) + PathDelim + DBObj.Database + PathDelim;
+    DbDir := IncludeTrailingPathDelimiter(GetOutputFilename(comboExportOutputTarget.Text, DBObj)) + DBObj.Database + PathDelim;
     if not DirectoryExists(DbDir) then
       ForceDirectories(DbDir);
     ExportStream := TFileStream.Create(DbDir + DBObj.ObjType.ToLower + '-' + DBObj.Name+'.sql', fmCreate or fmOpenWrite);