test_time_tz.rb: has_lisbon_tz

* test/ruby/test_time_tz.rb (has_lisbon_tz): separate from
  has_right_tz.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47212 b2dd03c8-39d4-4d8f-98ff-823fe69b080e