Update begin chain element

[denis-tingaikin]

We've discovered that if we update begin close logic it fixes all iface leaks

[NikitaSkrynnik]

@edwarnicke

We discussed the fix with timeout chain element and we think there is a problem with it.

If forwarder fails somewhere in the middle of its chain during request, there are two situations:

1. Datapath is already configured
   In this case we must keep the connection alive as much as possible so timeout should be set to maximum value (lifetime of a token)

2. Datapath is not configured yet
   In this case we should call Close as soon as possible to release the resources. timeout (or another chain element) should call Close immediately after receiving the error.

If timeout is always set to the maximum value and waits before closing then we don't release the resources in the second scenario.

The problem is that we can't check whether datapath is configured or not when we get the error on the forwarder