Changing zone name without changing file name is not handled properly

If zone name is changed by introducing/changing `$ORIGIN` directive on the top of the zone file, `dzonegit` will not properly reconfig nameservers, instead, it will try to reload zone, whose name is not yet known.

Also, when BIND is used, any journal file has to be deleted when changing zone name, otherwise BIND will refuse to load the zone. 