validate group when auto create subscription group

[yuz10]

1. Please describe the issue you observed:

• What did you do (The steps to reproduce)?
  the group that contains invalid charactors is able to be auto created. Some clients don't check subscription group.

• What is expected to see?

• What did you see instead?

2. Please tell us about your environment:

3. Other information (e.g. detailed explanation, logs, related issues, suggestions on how to fix, etc):