fix imap message count updates

Hi,

i used the hollidays to play around with the conky imap command.
First thing i noticed was that i got no changes with imap_unseen
command either when i read or delete a mail.
After checking that my arguments where ok i looked at the code.

I changed the condition that mades updates occur and forced conky
to update on any event that occures in IDLE mode. My imap server (dovecot)
accepts this but always complains that my client is broken because i
trigger a STATUS command on a folder i have already SELECTed.
OK, this was the same with the old code and now it seems to work at
least.

Can you please review this and consider about adding it.
I don't know if this is also relevant for 1.9.1 or master.
If so i could make a patch for those too.

Greetz
   Georg Hopp