prevent "config.log_level" DEPRECATION WARNING

DEPRECATION WARNING: You did not specify a `log_level` in `production.rb`.
Currently, the default value for `log_level` is `:info` for the production environment
and `:debug` in all other environments.
In Rails 5 the default value will be unified to `:debug` across all environments.
To preserve the current setting, add the following line to your `production.rb`:

   config.log_level = :info

git-svn-id: http://svn.redmine.org/redmine/trunk@13899 e93f8b46-1217-0410-a6f0-8f06a7374b81

config/environments/production.rb

@@ -1,6 +1,8 @@
 Rails.application.configure do
   # Settings specified here will take precedence over those in config/application.rb
 
+  config.log_level = :info
+
   # Code is not reloaded between requests.
   config.cache_classes = true