listunspent's new include_unsafe parameter doesn't work

    $ ./bitcoin-cli listunspent 0 9999999 '[]' true
    error code: -3
    error message:
    Expected type bool, got string

`rpc/client.cpp` probably needs to list the parameter along with the other 3:

        { "listunspent", 0, "minconf" },
        { "listunspent", 1, "maxconf" },
        { "listunspent", 2, "addresses" },

Add this?

        { "listunspent", 3, "include_unsafe" },
