Bug 30540: eval on set_time_zone

Bug 30540: eval on set_time_zone

This patch adds an eval around the call to set_time_zone so that we
don't crash on invalid local dates and instead just keep the passed
floating timezone.

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
(cherry picked from commit 6dab34fe66d41b367141f8e1b96abfe1729d045b)

Signed-off-by: Andrew Fuerste-Henry <andrew@bywatersolutions.com>