remote: fix dom->id after virDomainCreateWithFlags

remote: fix dom->id after virDomainCreateWithFlags

The same issue as (already fixed) in virDomainCreate -
REMOTE_PROC_DOMAIN_CREATE_WITH_FLAGS doesn't return new domain ID, only
-1 on error or 0 on success.

Besides this one fix it is more general problem - local domain object
ID can desynchronize with the real one, for example in case of another
client creates/destroys domain in the meantime. Perhaps virDomainGetID
should be called remotely (with all performance implications...)? Or
some event-based notification used?

Signed-off-by: Marek Marczykowski <marmarek@invisiblethingslab.com>