FIX: Rails.logger isn't always available when loading plugin locales

lib/plugin/instance.rb

@@ -591,7 +591,13 @@ JS
         DiscoursePluginRegistry.register_locale(locale, opts)
         Rails.configuration.assets.precompile << "locales/#{locale}.js"
       else
-        Rails.logger.error "Invalid locale! #{opts.inspect}"
+        msg = "Invalid locale! #{opts.inspect}"
+        # The logger isn't always present during boot / parsing locales from plugins
+        if Rails.logger.present?
+          Rails.logger.error(msg)
+        else
+          puts msg
+        end
       end
     end
   end