Kmail: mail expire switch disabled -> workaround

[Dominique Dumont <dominique.dumont@netc.fr>]

Hi

Following latest release, I can no longer switch the mail expire setup.

To reproduce:
- right click on a mail folder 
- click "Expire..."
- click on "Expire read messages after..." switch -> no change
- click on "Expire read" -> no change
- Click on "messages after..." -> the switch is flipped

All other buttons and widgets are working properly.

It's quite weird that the switch can be flipped only by clicking on the end of 
the label...

What's funny is I found this workaround while writing this mail...

Hope this helps