Correctly process anon_auth option for eldap:open()

Previously, it was impossible to set anon_auth to true. Making it
difficult to anonymously bind:

    1> {ok, Conn} = eldap:open(["localhost"], [{anon_auth, true}]).
    {ok,<0.34.0>}
    2> eldap:simple_bind(Conn, "", "").
    {error,anonymous_auth}

With this change:

    1> {ok, Conn} = eldap:open(["localhost"], [{anon_auth, true}]).
    {ok,<0.34.0>}
    2> eldap:simple_bind(Conn, "", "").
    ok

NB: Users could previously work around this by calling simple_bind as
follows:

    eldap:simple_bind(Conn, anon, anon)

0 files changed, 0 insertions, 0 deletions