Update Surfnet composer dependencies

composer.json

@@ -12,16 +12,6 @@
     },
     "minimum-stability": "dev",
     "prefer-stable": true,
-    "repositories": [
-        {
-            "type": "vcs",
-            "url": "https://github.com/OpenConext/Stepup-Middleware-clientbundle"
-        },
-        {
-            "type": "vcs",
-            "url": "https://github.com/OpenConext/Stepup-bundle"
-        }
-    ],
     "require": {
         "php": "~7.2",
         "ext-json": "*",
@@ -33,7 +23,7 @@
         "openconext/monitor-bundle": "^3.1",
         "sensio/framework-extra-bundle": "^5.0",
         "surfnet/stepup-bundle": "^5.0",
-        "surfnet/stepup-middleware-client-bundle": "dev-feature/self-asserted-tokens",
+        "surfnet/stepup-middleware-client-bundle": "^4.1",
         "surfnet/stepup-saml-bundle": "^4.3.1",
         "symfony/console": "4.4.*",
         "symfony/expression-language": "4.4.*",