Use JoinPath

This avoids issues where parts of the URL are discarded.

cmd/csaf_checker/links.go

@@ -9,6 +9,7 @@
 package main
 
 import (
+	"github.com/gocsaf/csaf/v3/internal/misc"
 	"io"
 	"net/http"
 	"net/url"
@@ -93,7 +94,7 @@ func (pgs pages) listed(
 				return err
 			}
 			// Links may be relative
-			abs := baseURL.ResolveReference(u).String()
+			abs := misc.JoinURL(baseURL, u).String()
 			content.links.Add(abs)
 			return nil
 		})