Add console appender to deprecated settings test

This commit enables the console appender for the settings deprecation
logger used in the deprecated settings logging test. This output will be
useful if this test fails again (it failed once mysteriously).

qa/evil-tests/src/test/resources/org/elasticsearch/common/logging/settings/log4j2.properties

@@ -21,5 +21,6 @@ appender.deprecation_file.layout.pattern = [%p][%l] %marker%m%n
 
 logger.deprecation.name = org.elasticsearch.deprecation.common.settings
 logger.deprecation.level = warn
+logger.deprecation.appenderRef.deprecation_console.ref = console
 logger.deprecation.appenderRef.deprecation_file.ref = deprecation_file
 logger.deprecation.additivity = false