On removing bots worse than SittingDuck

And NOT everybody is getting 100% against worst bots. e.g. ags.RougeDC is getting around 50% against aaa.WorstBot, which must indicate a bug.

And, removing ten 100% APS bots will decrease everyone by 1.0 APS, which is considerable. Although the rank is not affected by much, doing so destroys the existing meaning of ranges of APS. e.g. 90 used to be a barrier of the extremely strong bots, but if we remove 10 100% APS bots, the barrier will be 89. A big shift in everything is very inconvenience.