Silence WebRick output in tests

Author: p0deje

rb/spec/integration/selenium/webdriver/spec_support/rack_server.rb

@@ -48,7 +48,7 @@ def start
         end
 
         def run
-          handler.run @app, Host: @host, Port: @port, AccessLog: []
+          handler.run @app, Host: @host, Port: @port, AccessLog: [], Logger: WEBrick::Log.new(nil, 0)
         end
 
         def where_is(file)