Copy config file to staging if it doesn't exist there.

Fix #1823.

Author: me21

lib/fpm/package/deb.rb

@@ -1151,6 +1151,7 @@ def add_path(path, allconfigs)
             logger.debug("Adding config file #{path} to Staging area #{staging_path}")
             FileUtils.mkdir_p(File.dirname(dcl))
             FileUtils.cp_r path, dcl
+            add_path(path, allconfigs)
           else
             logger.debug("Config file aready exists in staging area.")
           end