LightweightHttpWagon is not using bulletproof URL.openConnexion(Proxy)

LightweightHttpWagon is messing (even in current trunk r68207) with System.setProperty( "http.proxyHost", proxyInfo.getHost() ); in it's openConnectionInternal method.

It's clearly not thread safe and a preferred method would be to use URL.openConnexion(Proxy).

From my point of view, before any call to URL.openConnexion, one should call java.net.ProxySelector#select(URI) and use one (if not every) java.net.Proxy given in the list.
java.net.Proxy handles care for proxy host and port while java.net.ProxySelector is dealing with nonProxyHost and http/https proxy differenciation