It seems confusing to call GetAdjustedTime there, because no offset could have been retrieved from the network at this point. Even if connman was started, timedata needs at least 5 peer connections to calculate an offset.

Fix the confusion by replacing GetAdjustedTime with GetTime, which does not change behavior.

Also:

    Replace magic number with MAX_FUTURE_BLOCK_TIME to clarify the context
    Add test, which passes both on current master and this pull request
    An unrelated refactoring commit, happy to drop

ninja all check-all