win32/test_console_attr.rb: reset attributes

* ext/-test-/win32/console/attribute.c (console_set_attribute):
  set console attribute.

* test/-ext-/win32/test_console_attr.rb (reset): reset attributes.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47242 b2dd03c8-39d4-4d8f-98ff-823fe69b080e