Suppress Ruby warnings about power_assert

Was a failed build in #86.

Author: olleolleolle

test/cgi/test_cgi_escape.rb

@@ -63,7 +63,7 @@ def test_cgi_unescape_accept_charset
     return unless defined?(::Encoding)
 
     assert_raise(TypeError) {CGI.unescape('', nil)}
-    assert_separately(%w[-rcgi/escape], "#{<<-"begin;"}\n#{<<-"end;"}")
+    assert_separately(%w[-W0 -rcgi/escape], "#{<<-"begin;"}\n#{<<-"end;"}")
     begin;
       assert_equal("", CGI.unescape(''))
     end;
@@ -120,7 +120,7 @@ def test_cgi_unescapeURIComponent_accept_charset
     return unless defined?(::Encoding)
 
     assert_raise(TypeError) {CGI.unescapeURIComponent('', nil)}
-    assert_separately(%w[-rcgi/escape], "#{<<-"begin;"}\n#{<<-"end;"}")
+    assert_separately(%w[-W0 -rcgi/escape], "#{<<-"begin;"}\n#{<<-"end;"}")
     begin;
       assert_equal("", CGI.unescapeURIComponent(''))
     end;