Fix encoding of the query part of an URL [Issue 20507].

src/url_canon_relative.cc

Index: src/url_canon_relative.cc
===================================================================
--- src/url_canon_relative.cc	(revision 118)
+++ src/url_canon_relative.cc	(working copy)
@@ -351,7 +351,8 @@
   if (query.is_valid()) {
     // Just the query specified, replace the query and reference (ignore
     // failures for refs)
-    CanonicalizeQuery(relative_url, query, NULL, output, &out_parsed->query);
+    CanonicalizeQuery(relative_url, query, query_converter,
+                      output, &out_parsed->query);
     CanonicalizeRef(relative_url, ref, output, &out_parsed->ref);
     return success;
   }