docs: updated GoReport card

README.md

@@ -3,7 +3,7 @@
 [![release](https://git.martin-riedl.de/golang/httprouter/badges/release.svg)](https://git.martin-riedl.de/golang/httprouter/tags)
 [![pipeline status](https://git.martin-riedl.de/golang/httprouter/badges/workflows/build.yml/badge.svg)](https://git.martin-riedl.de/golang/httprouter/actions)
 [![GoDoc](https://godoc.org/gitlab.com/martinr92/gohttprouter?status.svg)](https://godoc.org/gitlab.com/martinr92/gohttprouter)
-[![Go Report Card](https://goreportcard.com/badge/gitlab.com/martinr92/gohttprouter)](https://goreportcard.com/report/gitlab.com/martinr92/gohttprouter)
+[![Go Report Card](https://goreportcard.com/badge/git.martin-riedl.de/golang/httprouter/v4)](https://goreportcard.com/report/git.martin-riedl.de/golang/httprouter/v4)
 
 httprouter is a framework used for HTTP request routing.