LogConfigurator resolveConfig  also reads .rpmnew or .bak files

Currently the LogConfigurator will attempt to read any file that starts with "logging." in the env.configFile() path.

A common practise is to suffix files with .bak or in case of package managers they often add a suffix if the file has been modified upstream.

Elasticsearch will read those values anyway and that might lead to very confusing logging behaviour.

I am not sure how to best approach this, either have a whitelist or a backlist of suffixes that are allowed/disallowed ?
Without the changes in this PR it would match as anything starting with `logging.` matches. 
So maybe the allowed suffixes should be

    (".YML", ".YAML", ".JSON", ".PROPERTIES", ".yml", ".yaml", ".json", ".properties");

?