0.8.8claws71

* src/compose.c
* src/gtk/menu.[ch]
        fix wrong selecting of mime encoding type, when
        opening property dialog of attachments in the
        compose window. 7bit was always selected and that
        destoryed files with 8bit data.
        (closes bug #9 Sylpheed-claws destroys attachments when
         changing MIME-types)