Fixed logical flaw in updating a blogs title

stubb

@@ -190,7 +190,7 @@ function update_favorite()
     local item = session.favorites[id]
     if item then
       print(string.format('Old title: %s', item.display))
-      while title ~= '' do
+      while not title or title == '' do
         io.write('Enter new title (! to cancel) > ')
         title = io.read()
         if title == '!' then return print('Cancelled') end