standard forum for general use can have multiple discussions, whereas simple single discussion forum can only have one. Should user be allowed to change forum type from standard forum for general use to simple single discussion forum.

Problem:
In simple single discussion forum subject and message of discussion is same as forum name and introduction. Changing forum type between simple single discussion forum and standard forum for general use changes existing discussion.
Steps to reproduce:

1. Create a new standard forum for general use forum
2. Add two discussions
3. Change forum type from standard forum for general use to simple single discussion forum
4. Check discussion subject and message is replaced with forum name and introduction.
5. Change forum type to standard forum for general use and it retains forum name and introduction for that discussion.