providers/http: Don't accept redirect codes outside 3XX range

providers/http/http.go

@@ -73,6 +73,11 @@ func funcError (status int, message any) (string, error) {
 }
 
 func funcRedirect (status int, pat string) (string, error) {
+	if status < 300 || status > 399 {
+		return "", fmt.Errorf(
+			"provided status code %d is not in the 3XX range",
+			status)
+	}
 	return "", shttp.Redirect {
 		Status:   status,
 		Location: pat,