• Set WORKERS_PER_CORE by default to 1, as it shows to have the best performance on benchmarks.
• Make the default web concurrency, when WEB_CONCURRENCY is not set, to a minimum of 2 workers. This is to avoid bad performance and blocking applications (server application) on small machines (server machine/cloud/etc). This can be overridden using WEB_CONCURRENCY. This applies for example in the case where WORKERS_PER_CORE is set to 1 (the default) and the server has only 1 CPU core. PR #6 and PR #5 in parent image.