According to Android documentation, the column uid2445 should be available since API level 17, i.e. Android 4.2.2.
So, ical4android expects uid2445 on API level 17+, but in your case, you have Android 4.2.2, but the column isn’t there. You can try to reset your calendar storage (Settings / Apps / Calendar Storage / Delete data) and add the DAVdroid account again. If it still doesn’t work, I’d suggest to use another firmware which behaves as documented (either a firmware update from your manufacturer, if available, or a custom ROM like CyanogenMod).