add unused index.html to make <welcome-file-list> work
add unused index.html to make <welcome-file-list> work

(cf http://www.enavigo.com/2008/11/21/jetty-6-welcome-file-how-to-use-a-servlet-to-handle-your-welcome-file/)

EsupPortail/esup-smsu-api-admin,EsupPortail/esup-smsu-api-admin,EsupPortail/esup-smsu-api-admin