fix(dateHandling): trouble with dates from appointment

[stenjo]

Handling offset datetimes still a problem. Today seems to be handled, but when the appointment record only has a date, we're getting problems:

None
Version:  1.2.1
Created device
dt:     2023-11-09 13:15:00+01:00
today:  2023-11-07 18:24:49.454196+00:00
dt:     2023-11-11 00:00:00
today:  2023-11-07 18:24:49.454196+00:00
Traceback (most recent call last):
  File "/home/pi/Middager/middag.py", line 114, in <module>
    main(sys.argv[1:])
  File "/home/pi/Middager/middag.py", line 109, in main
    msg = dayText(event)
  File "/home/pi/Middager/dateHandling.py", line 21, in dayText
    delta = dt - today
TypeError: can't subtract offset-naive and offset-aware datetimes