Hotfix the DOI url in the frontend

dbrepo-ui/config.js

@@ -16,5 +16,6 @@ config.tokenMax = process.env.TOKEN_MAX || 5
 config.elasticPassword = process.env.ELASTIC_PASSWORD || 'elastic'
 config.clientSecret = process.env.DBREPO_CLIENT_SECRET || 'MUwRc7yfXSJwX8AdRMWaQC3Nep1VjwgG'
 config.defaultPublisher = process.env.DEFAULT_PID_PUBLISHER || 'Technische Universität Wien'
+config.doiUrl = process.env.DOI_URL || 'https://doi.org'
 
 module.exports = config