QtIFW

Fix timezone issue, simply keep the UTC time.

Since we're the only user of the list archive function, do
not convert from UTC. Though once we document the function
it should be mentioned that the user needs to convert it
(e.g. for display purposes etc...).

Change-Id: Icbf8372ddff4f34e3c5a426b983ff25a117d74eb
Reviewed-by: Katja Marttila <katja.marttila@theqtcompany.com>