Avoid long timeout on connect attempt to non-existend IP address

When an application tries to connect to an non-existent IP address, the current implementation sends roughly 30 ARP requests before giving up. (Five ARPs for each of the six SYN retries). This results in a long timeout of 32 seconds.

In case the initial ARP resolution with five retries fails, it makes not much sense to further retry the connection attempt since the ARP address resolving will most likely continue to fail.

The implementation is changed, such that the TCP connect attempt will be aborted right after the arp resolution failure.