Update htdocs/_i18n/en/pages/howtos/upgrade-ecloud-storage.md,...

Update htdocs/_i18n/en/pages/howtos/upgrade-ecloud-storage.md, htdocs/images/howtos/ecloud/checkout-murena.png, htdocs/images/howtos/ecloud/files-app-murena.png, htdocs/images/howtos/ecloud/murena-dashboard.png, htdocs/images/howtos/ecloud/subscriptions-page-no-login.png, htdocs/images/howtos/ecloud/subscriptions-page-login.png