Socket option shoud be set as CRuby's test does.
Socket option shoud be set as CRuby's test does.

This fixes FTP specs failure with Net::ReadTimeout on Solaris 10.
The socket option is the same as that of CRuby's FTPTest#create_ftp_server
at test/net/ftp/test_ftp.rb line 1635 (as of svn r52298).

nobu/rubyspec,sgarciac/spec,BanzaiMan/rubyspec,wied03/rubyspec,wied03/rubyspec,kachick/rubyspec,kachick/rubyspec,sgarciac/spec,nobu/rubyspec,kachick/rubyspec,ruby/rubyspec,eregon/rubyspec,ruby/spec,BanzaiMan/rubyspec,ruby/spec,nobu/rubyspec,eregon/rubyspec,ruby/spec,wied03/rubyspec,sgarciac/spec,ruby/rubyspec,eregon/rubyspec