SSL Verify

Hi,

I'm trying to connect via a Proxy (inside corp network, I can't choose not to)
I have, of course, replaced the USER PASS & PROXY_URL text
First the error message, perhaps this is the wrong place to report it so there would be no point reading the rest :)

> Assertion failure: 0 != rv, at ntio.c:1803
>
> Please submit a bug report with steps to reproduce this fault, and any error messages that follow (in > their entirety). Thanks.
> Exception: EXCEPTION_BREAKPOINT at 0x7ff9caa7e0e2 -- DebugBreak at C:\windows\system32\KERNELBASE.dll (unknown line)
> DebugBreak at C:\windows\system32\KERNELBASE.dll (unknown line)

So here I am submitting this bug report. Can I also add that if it is a Julia error message, it should include a guide to where to report this bug. Thanks

My code :

```
using HTTPClient.HTTPC
using LibCURL

const CHECK_SSL = false

function customize_curl(curl)
# removed error trapping for clarity
LibCURL.curl_easy_setopt(curl, LibCURL.CURLOPT_PROXY, "http://USER:PASS@PROXY_URL")
LibCURL.curl_easy_setopt(curl, LibCURL.CURLOPT_PROXYPORT, 8080)
LibCURL.curl_easy_setopt(curl, LibCURL.CURLOPT_SSL_VERIFYPEER, CHECK_SSL)
end

r = HTTPC.get("https://news.ycombinator.com/news",
RequestOptions(request_timeout=5.0,callback=customize_curl)
)
println(r)
```

if CHECK_SSL is true I get

ERROR: LoadError: "Error executing request : Problem with the SSL CA cert (path? access rights?)"

which is a known problem, but to see here how to set options for CA checking
https://curl.haxx.se/docs/sslcerts.html

> Tell libcurl to not verify the peer. With libcurl you disable this with curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, FALSE);
> With the curl command line tool, you disable this with -k/--insecure.

so I added CHECK_SSL and set to false and then get the error message at the top.