test_signal.rb: remove stale test
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47665 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
test_signal.rb: remove stale test
remove stale test. signals are delivered to the main thread
always now, so sleep in sub thread is no longer interrupted.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47665 b2dd03c8-39d4-4d8f-98ff-823fe69b080e