hugolib: Fix RSSLink vs RSS Output Format

Fixes #3450

hugolib/site.go

@@ -1139,7 +1139,11 @@ func (s *Site) initializeSiteInfo() {
 		s:                              s,
 	}
 
-	s.Info.RSSLink = s.permalink(lang.GetString("rssURI"))
+	rssOutputFormat, found := s.outputFormats[KindHome].GetByName(output.RSSFormat.Name)
+
+	if found {
+		s.Info.RSSLink = s.permalink(rssOutputFormat.BaseFilename())
+	}
 }
 
 func (s *Site) dataDir() string {

hugolib/site_output_test.go

@@ -284,4 +284,9 @@ baseName = "feed"
 
 	th.assertFileContent("public/feed.xml", "Recent content on")
 
+	s := h.Sites[0]
+
+	//Issue #3450
+	require.Equal(t, "http://example.com/blog/feed.xml", s.Info.RSSLink)
+
 }