* lib/net/imap.rb (Net::IMAP#initialize): Close the opened socket when
  any exception occur.
  This fixes a fd leak by IMAPTest#test_imaps_post_connection_check
  which start_tls_session() raises an exception.




git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46210 b2dd03c8-39d4-4d8f-98ff-823fe69b080e