HTTPCLIENT-1535: Permit other addresses to be tried in the event of a NoRouteToHostException.  e.g. when there one of the addresses to be used is an ipv6 address when the client does not have an ipv6 route to that particular host

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpclient/branches/4.3.x@1616238 13f79535-47bb-0310-9956-ffa450edef68