Update docs for Python agent's renamed log_ecs_reformatting

Author: basepi

docs/setup.asciidoc

@@ -191,7 +191,7 @@ from the https://github.com/elastic/apm-agent-python[Elastic APM Python agent] i
 https://www.elastic.co/guide/en/apm/agent/python/current/log-correlation.html[correlate logs to spans, transactions and traces] in Elastic APM.
 
 You can also quickly turn on ECS-formatted logs in your python app by setting
-https://www.elastic.co/guide/en/apm/agent/python/master/configuration.html#config-log_ecs_formatting[`LOG_ECS_FORMATTING=override`]
+https://www.elastic.co/guide/en/apm/agent/python/master/configuration.html#config-log_ecs_reformatting[`LOG_ECS_REFORMATTING=override`]
 in the Elastic APM Python agent.
 
 [float]