pc5: fix guessing of year
pc5: fix guessing of year

as packets don't store the year of recording, we pick the current year and
guess, if the recording is from previous year.

unfortunatly the comparison was wrong. So we used previous year whenever
we downloaded data from a previous month.

rclasen/srmio,rclasen/srmio,rclasen/srmio,rclasen/srmio