Use os.time() in database.lua
Comment in database.lua:
-- DIRTY: return a string to put in a database query which gets the
-- current time (in seconds since the epoch, UTC).
-- (This should be replaced with Lua os.time() once the script has access
-- to this, see <https://www.hostedredmine.com/issues/657141>.)
This is possible in S3_0 and later.