Update license headers

apps/files/admin.php

apps/files/ajax/delete.php

apps/files/ajax/download.php

apps/files/ajax/getstoragestats.php

apps/files/ajax/list.php

apps/files/ajax/mimeicon.php

apps/files/ajax/move.php

apps/files/ajax/newfile.php

apps/files/ajax/newfolder.php

apps/files/ajax/rename.php

apps/files/ajax/scan.php

apps/files/ajax/upload.php

apps/files/appinfo/app.php

apps/files/appinfo/application.php

apps/files/appinfo/register_command.php

apps/files/appinfo/remote.php

apps/files/appinfo/routes.php

apps/files/command/scan.php

apps/files/controller/apicontroller.php

apps/files/download.php