Try faster new gateways

Currently we've implemented a reconnect-scheme (4x reconnection after failure with delay of 2 seconds, 1x reconnection after failure with delay of 4) that will be tried before the client tries to connect to another gateway. This reconnection scheme doesn't work well if the failure is a HTTP connection timeout by a missing response from the server because one timeout is already 30+ seconds. In that case the user has to wait too long until another gateway will be tried out. This results in users stopping the connection setup process manually before Bitmask had a chance to check all possible connections. To avoid that we should restrict the number of connection retries during the VPN setup to 2.