CVE-2015-5370: s4:rpc_server: return the correct secondary_address in dcesrv_bind()

For now we still force \\PIPE\\ in upper case, we may be able to remove
this and change it in our idl files later. But for now we better
behave like a windows server without changing too much.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=11344

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Günther Deschner <gd@samba.org>
