manually restoring a snapshot of the build can result in missing chroot/em-config*

[jonesmz]

Better would be for each parser script to add the em-config and em-config.json prior to executing the parser specific code, and remove them after it's done.

In this way, if the current chroot is missing those files, it doesn't matter, because they weren't expected (and shouldn't be there anyway) in the first place.