Currently we wrongly calculate the new block age to
old * LAST_AGE_WEIGHT / 100.
Fix it to new * (100 - LAST_AGE_WEIGHT) / 100
+ old * LAST_AGE_WEIGHT / 100.
Signed-off-by: qixiaoyu1 <qixiaoyu1@xxxxxxxxxx>
Signed-off-by: xiongping1 <xiongping1@xxxxxxxxxx>