Remove an unused variable to suppress a warning.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56851 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/net/ftp.rb

@@ -557,7 +557,7 @@ module Net
           if !resp.start_with?("1")
             raise FTPReplyError, resp
           end
-          conn, peeraddr = sock.accept
+          conn, = sock.accept
           sock.shutdown(Socket::SHUT_WR) rescue nil
           sock.read rescue nil
         ensure