If a proxy is needed, for example because the computer is behind a corporate proxy,
it can be set as follows: proxy = "http://your-proxy.net:port/" or
"https://your-proxy.net:port/" and "proxyuserpwd" = "user:pwd".
Usage
set_proxy(proxy, proxyuserpwd)
Arguments
proxy
character, the URL of the proxy ("https://your-proxy.net:port/").
proxyuserpwd
character, user and password for the authentication ("user:pwd").