php.ini: set date.timezone

Set date.timezone in php.ini to match time zone settings.
Prevents a warning being logged about it not being set
each time a PHP date/time method is used.

Signed-off-by: Floris Bos <bos@je-eigen-domein.nl>
Reviewed-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>