Use https instead of http

Author: znz

test/rdoc/test_rdoc_markup_to_markdown.rb

@@ -363,9 +363,9 @@ def test_convert_RDOCLINK_image
 
   def test_convert_TIDYLINK
     result = @to.convert \
-      '{DSL}[http://en.wikipedia.org/wiki/Domain-specific_language]'
+      '{DSL}[https://en.wikipedia.org/wiki/Domain-specific_language]'
 
-    expected = "[DSL](http://en.wikipedia.org/wiki/Domain-specific_language)\n"
+    expected = "[DSL](https://en.wikipedia.org/wiki/Domain-specific_language)\n"
 
     assert_equal expected, result
   end