Modified client to send a PUSH_REQUEST message to server 1 second

Modified client to send a PUSH_REQUEST message to server 1 second
after connection initiation rather than 0 seconds after.
Successive PUSH_REQUEST messages after the first will continue to be
sent at 5 second intervals until a response is received.  This tends
to speed up the client connection sequence by 4 seconds because the
first PUSH_REQUEST message is usually sent too soon and is dropped,
causing a wait of 5 seconds until the next PUSH_REQUEST message is
sent.

Version 2.1_rc19d

git-svn-id: http://svn.openvpn.net/projects/openvpn/branches/BETA21/openvpn@4965 e7ae566f-a301-0410-adde-c780ea21d3b5