admin: Fix passing an incorrect readonly attribute to virNetServerServiceNew

admin: Fix passing an incorrect readonly attribute to virNetServerServiceNew

When registering admin UNIX socket, a new service is created for it. This
service is incorrectly initialized to be readonly, which is later inherited by
all clients connected to the socket. In libvirt-admin's case there currently
isn't any use for the attribute anyway, but since the socket has root-only
access permissions, the least we can do is to make every admin client
connected to it report readonly as false.

Signed-off-by: Erik Skultety <eskultet@redhat.com>