Fix build problem on Ruby 2.2.

www/ruby-webunit/distinfo

@@ -1,5 +1,6 @@
-$NetBSD: distinfo,v 1.4 2006/01/03 14:25:51 taca Exp $
+$NetBSD: distinfo,v 1.5 2015/06/11 17:10:46 taca Exp $
 
 SHA1 (webunit-20040429++.tar.gz) = dfc317b7318731e56dadfe4f7d11acc66f54fa29
 RMD160 (webunit-20040429++.tar.gz) = db2416e67ffc178a2d8965cdce312c2407d560ca
 Size (webunit-20040429++.tar.gz) = 59312 bytes
+SHA1 (patch-install.rb) = deed7b29562ddb8a14f3bee1815a99967a403ea1

www/ruby-webunit/patches/patch-install.rb

@@ -0,0 +1,24 @@
+$NetBSD: patch-install.rb,v 1.1 2015/06/11 17:10:46 taca Exp $
+
+Fix build problem on Ruby 2.2 and later.
+
+--- install.rb.orig	2003-01-21 11:50:39.000000000 +0000
++++ install.rb
+@@ -45,7 +45,7 @@ end
+ 
+ class ConfigTable
+ 
+-  c = ::Config::CONFIG
++  c = ::RbConfig::CONFIG
+ 
+   rubypath = c['bindir'] + '/' + c['ruby_install_name']
+ 
+@@ -691,7 +691,7 @@ class Installer
+         "no extention exists: Have you done 'ruby #{$0} setup' ?"
+   end
+ 
+-  DLEXT = /\.#{ ::Config::CONFIG['DLEXT'] }\z/
++  DLEXT = /\.#{ ::RbConfig::CONFIG['DLEXT'] }\z/
+ 
+   def _allext( dir )
+     Dir.open(dir) {|d|