plumbing: Also set timestamp of last update in job.
plumbing: Also set timestamp of last update in job.

This should simplify job reports.

JesseWeinstein/ArchiveBot,JesseWeinstein/ArchiveBot,falconkirtaran/ArchiveBot,falconkirtaran/ArchiveBot,emijrp/ArchiveBot,falconkirtaran/ArchiveBot,Frogging101/ArchiveBot,JesseWeinstein/ArchiveBot,Asparagirl/ArchiveBot,Frogging101/ArchiveBot,JesseWeinstein/ArchiveBot,Asparagirl/ArchiveBot,emijrp/ArchiveBot,falconkirtaran/ArchiveBot,falconkirtaran/ArchiveBot,emijrp/ArchiveBot,ArchiveTeam/ArchiveBot,emijrp/ArchiveBot,emijrp/ArchiveBot,ArchiveTeam/ArchiveBot,Frogging101/ArchiveBot,Asparagirl/ArchiveBot,ArchiveTeam/ArchiveBot,Frogging101/ArchiveBot,JesseWeinstein/ArchiveBot,ArchiveTeam/ArchiveBot,ArchiveTeam/ArchiveBot,Frogging101/ArchiveBot,Asparagirl/ArchiveBot,Asparagirl/ArchiveBot