don't allow values just below typemax(Clong) in set_timeout

[manuelbb-upb]

The set_timeout function in src/Curl/Easy.jl checks the argument timeout against typemax(Clong).
But (at least in my case) setopt(easy, CURLOPT_TIMEOUT, typemax(Clong)) leads to

Error: curl_easy_setopt: 43

which is a CURL_BAD_FUNCTION_ARGUMENT.
From the C Code I would guess that checking against typemax(Clong) ÷ 1000 is more appropriate.
Simply plugging that in gives:

function set_timeout(easy::Easy, timeout::Real)
    timeout > 0 ||
        throw(ArgumentError("timeout must be positive, got $timeout"))
    _max = typemax(Clong) ÷ 1000
    if timeout ≤ _max
        timeout_ms = round(Clong, timeout * 1000)
        setopt(easy, CURLOPT_TIMEOUT_MS, timeout_ms)
    else
        timeout = timeout ≤ _max ? round(Clong, timeout) : Clong(0)
        setopt(easy, CURLOPT_TIMEOUT, timeout)
    end
end

But the second conditional is redundant and the above is equivalent to

function set_timeout(easy::Easy, timeout::Real)
    timeout > 0 ||
        throw(ArgumentError("timeout must be positive, got $timeout"))
    _max = typemax(Clong) ÷ 1000
    if timeout ≤ _max
        timeout_ms = round(Clong, timeout * 1000)
        setopt(easy, CURLOPT_TIMEOUT_MS, timeout_ms)
    else
        setopt(easy, CURLOPT_TIMEOUT, Clong(0))
    end
end

[StefanKarpinski]

Thanks for the detailed bug report! I'll take a look.