test_rinda.rb: revert stop_service

* test/rinda/test_rinda.rb (test_take_bug_8215): revert
  `stop_service` for the time being.  need to reset
  `current_server` to let test/drb work, probably.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46140 b2dd03c8-39d4-4d8f-98ff-823fe69b080e