Starts from a snapshot taken on another server are up to 1.8 s faster

A sandbox started from a snapshot taken on another server trusts that server's outbound certificate in about 4 ms. In an image with certificate hooks (Java's keystore, say) it ran Debian's whole update-ca-certificates and took 0.7 to 1.8 s of the start. Snapshots taken from now on start this way; an older one does once it is taken again.