Looking over the code, this appears to be one "high risk but hopefully
unlikely that plugins are causing this to break", this line is however
redundant leftovers from spigots tick limiter patch, which should be
doing nothing as-is.
upstream was doing a containsKey/get pattern, and always doing it at that.
that scenario is only even valid if were in the middle of a block place.
Optimize to check if the captured list even has values in it, and also to
just do a get call since the value can never be null.
