Update CHANGELOG.md

Author: segasai

CHANGELOG.md

@@ -19,6 +19,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 ### Changed
 - Setting n_effective for Sampler.run_nested() and DynamicSampler.sample_initial(), and n_effective_init for DynamicSampler.run_nested(), are deprecated ( #379 ; by @edbennett )
 - The slice sampling can now switch to doubling interval expansion algorithm from Neal(2003), if at any point of the sampling the interval was expanded more than 1000 times. It should help slice/rslice sampling of difficult posteriors ( #382; by @segasai )
+- The accumulation of statistics using to tune proposal distribution is now more robust when multi-threading/pool is used. Previously statistics from every queue_size call were used and all other were discarded. Now the statistics are accumulated from all the parallel sampling calls. That should help sampling of complex distributions
 - The .update_proposal() function that updates the states of samplers
 now has an additional keyword which allows to either just accumulate the statistics from repeated function calls or actual update of the proposal. This was needed to not loose information when queue_size>1 (#385; by @segasai )