[CRIU] service: one connection -- multiple requests

[Ruslan Kuprieiev]

I have noticed that if program does something like this:
     -- ....
     -- ask to dump itself
     -- ask service to do something else
     -- ....

and then we are trying to restore it -- it will fail, as the service 
socket(that was created especially for this process) will be closed. 
Without multirequesting everything will be fine, as for every request 
the new one socket will be created.
I think we shouldn't reject multirequesting, because of it's goals: it 
is fast and a bit easy to work with. Maybe we should give user a choose 
somehow?