Please describe the problem:
If the the overide-namespace textbox is filled with something even if the
correspondig checkbox is uncheck, Evolution still use what the textbox contains.

Steps to reproduce:
1. Check the overide namespace checkbox
2. Fill the text box with something
3. Uncheck the checkbox (the textbox is greyed out)
4. Restart Evolution


Actual results:
Evolution still use this namespace when connecting to the imap server.

Expected results:
Evolution should use the server supplied namespace.

Does this happen every time?
Always

Other information:
Distribution: Ubuntu Breezy