[migration] don't attempt to carry over values when renaming a computed relation Without the fix in migractions.py, the introduced test crashes with an operational error because of an attempt to write to a non-existing relation table (computed relations are not materialized). Closes #6304946

etc/init.d
etc/cubicweb.d
etc/bash_completion.d
usr/bin
usr/share/doc/cubicweb-ctl
var/log/cubicweb
var/lib/cubicweb/backup
var/lib/cubicweb/instances