Thank you for your prompt help!
It works with the modification. But only when I modify the file inside the alfresco-repository-5.0.a.jar.
I have tryed to put the modified file-servers-context.xml in shared/classes/alfresco/subsystems/fileServers/default but it seems that the override is not hapening.
I have tryed to use shared/classes/alfresco /subsystems/fileServers /shared/class/alfresco/subsystems etc. but none works.
To override a file, is there another configuration I have to add? Or modify the name of the file?
Thanks