fixing another dead link

Co-authored-by: Anatoly Scherbakov <altaisoft@gmail.com>

Author: 2 people

README.rst

@@ -139,7 +139,7 @@ Quick Examples
     # document transformed into a particular tree structure per the given frame
 
     # normalize a document using the RDF Dataset Normalization Algorithm
-    # (URDNA2015), see: https://json-ld.github.io/rdf-dataset-canonicalization/spec/index.html
+    # (URDNA2015), see: https://www.w3.org/TR/rdf-canon/
     normalized = jsonld.normalize(
         doc, {'algorithm': 'URDNA2015', 'format': 'application/n-quads'})
     # normalized is a string that is a canonical representation of the document