* test/ruby/envutil.rb (assert_no_memory_leak): increase default value
  of `limit` keyword argument.
  assert_no_memory_leak occasionally fails with limit=1.5.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@45475 b2dd03c8-39d4-4d8f-98ff-823fe69b080e