wireguard: sending the first handshake

wireguard: sending the first handshake

After creating a peer, we send a handshake request. But it's not quite right
to call wg_send_keepalive() directly.
According to documentation, handshake initiation is sent after (REKEY_TIMEOUT + jitter) ms.
Since it's the first one - we don't need to take REKEY_TIMEOUT into account,
but we still have jitter.

It also makes no sense to immediately send keepalives,
because the connection is not created yet.

Type: fix

Signed-off-by: Artem Glazychev <artem.glazychev@xored.com>
Change-Id: I61707e4be79be65abc3396b5f1dbd48ecbf7ba60