docs(gin): Replace broken link to documentation with valid (#4064)

gin.go

@@ -598,7 +598,7 @@ func (engine *Engine) RunQUIC(addr, certFile, keyFile string) (err error) {
 
 	if engine.isUnsafeTrustedProxies() {
 		debugPrint("[WARNING] You trusted all proxies, this is NOT safe. We recommend you to set a value.\n" +
-			"Please check https://pkg.go.dev/github.com/gin-gonic/gin#readme-don-t-trust-all-proxies for details.")
+			"Please check https://github.com/gin-gonic/gin/blob/master/docs/doc.md#dont-trust-all-proxies for details.")
 	}
 
 	err = http3.ListenAndServeQUIC(addr, certFile, keyFile, engine.Handler())