wait ssl connect completion on client proxy path

Subject: [PATCH] We can ran into situation (at least on iOS) when with openssl
 nonblocking BIO and http proxy we don't perform ssl_connect straight away so
 we need to retry until we finish ssl_connect. If we don't do that we will
 fail in LWS_CONNMODE_WS_CLIENT_WAITING_PROXY_REPLY when testing for "HTTP/1.0
 200" successful connection.

Signed-off-by: shys <shyswork@zoho.com>