un.rb: HTTP-alt by default

* lib/un.rb (httpd): changed default port number to 8080 (HTTP
  Alternate), which does not need root privilege.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@50955 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/un.rb

@@ -319,6 +319,7 @@ def httpd
     [:Port, :MaxClients].each do |name|
       opt = options[name] and (options[name] = Integer(opt)) rescue nil
     end
+    options[:Port] ||= 8080     # HTTP Alternate
     unless argv.size == 1
       raise ArgumentError, "DocumentRoot is mandatory"
     end