[Dovecot] load increase after upgrade to 2.0.8

[Cor Bosman]

> 
> Correct. Only Linux is affected.
> 
> Anyway, Postfix's design has been like this forever, so no one would have ever noticed context switch counts increasing. But changing this might make them notice that context switches are dropping.
> 

Im a little surprised we havent seen more reports on dovecot as well. The impact was noticeable for us. 

Thanks for looking into the issue!

Cor