Add binmode for Tempfile to prevent EOF (0x1A)

http://ruby-mswin.cloudapp.net/vc10-x64/ruby-trunk/log/20151023T062322Z.log.html.gz

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52298 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/net/ftp/test_ftp.rb

@@ -796,6 +796,7 @@ class FTPTest < Test::Unit::TestCase
         assert_match(/\APASS /, commands.shift)
         assert_equal("TYPE I\r\n", commands.shift)
         Tempfile.create("foo", external_encoding: "ASCII-8BIT") do |f|
+          f.binmode
           buf = String.new
           res = ftp.getbinaryfile("foo", f.path) { |s|
             buf << s