Fix refresh admin token

doc/testing/postman/CAPIF.postman_collection.json

@@ -979,7 +979,7 @@
 						"exec": [
 							"var res = JSON.parse(responseBody);",
 							"",
-							"pm.environment.set('REFRESH_TOKEN', res.refresh_token);"
+							"pm.environment.set('ADMIN_TOKEN', res.access_token);"
 						],
 						"type": "text/javascript",
 						"packages": {}