Update Connection.cs to support null Proxy
Update Connection.cs to support null Proxy

Updated Connection class to set Proxy to null for HttpWebRequest's. Users who need to go via a web proxy may need customize this code. Ideally we could create a property on Connection called Proxy of type WebProxy and default set it to null in the Connection constructor
kangkot/ArangoDB-NET,yojimbo87/ArangoDB-NET