increase wait

http://chkbuild002.hsbt.org/chkbuild/ruby-trunk/log/20140518T160015Z.fail.html.gz

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46007 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/rake/test_rake_task.rb

@@ -270,7 +270,7 @@ class TestRakeTask < Rake::TestCase
     result = []
 
     t_a = task(:a) do |t|
-      sleep 0.02
+      sleep 0.2
       mx.synchronize { result << t.name }
     end