Use server_port for Windows

fix r41686 [Bug #8574]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41802 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/socket/test_tcp.rb

@@ -21,9 +21,13 @@ class TestSocket_TCPSocket < Test::Unit::TestCase
       TCPSocket.new(addr, server_port, addr, client_port)
       flunk "expected SystemCallError"
     rescue SystemCallError => e
+      if /mswin|mingw/ =~ RUBY_PLATFORM
+        assert_match "for \"#{addr}\" port #{server_port}", e.message
+      else
         assert_match "for \"#{addr}\" port #{client_port}", e.message
       end
     end
+  end
 
   def test_recvfrom
     svr = TCPServer.new("localhost", 0)