[rubygems/rubygems] Don't leave side effects on verbosity

https://github.com/rubygems/rubygems/commit/c58e711598

test/rubygems/test_gem_package_task.rb

@@ -9,9 +9,17 @@ class TestGemPackageTask < Gem::TestCase
     super
 
     Rake.application = Rake::Application.new
+
+    @original_rake_fileutils_verbosity = RakeFileUtils.verbose_flag
     RakeFileUtils.verbose_flag = false
   end
 
+  def teardown
+    RakeFileUtils.verbose_flag = @original_rake_fileutils_verbosity
+
+    super
+  end
+
   def test_gem_package
     gem = Gem::Specification.new do |g|
       g.name = "pkgr"