Update message-db version

Created by: wolfejw86

updating to message-db 1.2.6 in dockerfile and rundbscript

addresses #1 (closed)

Also I wasn't sure if you meant to keep postgres version 10, I have this working on postgres:13.3-alpine on my machine. I figured if you wanted to change pg versions you'd make a separate issue for that so I left that out for now :)

Hope this helps! Also happy to make any updates.