fix: rename OPENSEARCH_ANONYMOUS_AUTH to OPENSEARCH_ANONYMOUS_AUTH_ENABLED in .env (opensearch-project#115)

Author: kylehounslow

.env

@@ -25,7 +25,7 @@ OPENSEARCH_JAVA_OPTS=-Xms1g -Xmx1g
 
 # Anonymous Authentication
 # Set to true to allow access to OpenSearch/Dashboards without login
-OPENSEARCH_ANONYMOUS_AUTH=false
+OPENSEARCH_ANONYMOUS_AUTH_ENABLED=false
 
 # OpenSearch Dashboards Configuration
 OPENSEARCH_DASHBOARDS_VERSION=3.6.0