[server,bfss] fix storage migration when Bytes attributes is None (closes #13519541)
When a Bytes attributes is None before the BFSS storage migration,
the migration crashes. A Bytes attribute can be None, when the attribute
is not required and there is no default value. In this case, the attributes
should remained None after migration and no file is stored on the disk.
/var/log/cubicweb/*.log {
weekly
missingok
rotate 10
compress
delaycompress
notifempty
create 640 root adm
sharedscripts
postrotate
if [ -x /usr/sbin/invoke-rc.d ]; then \
invoke-rc.d cubicweb reload > /dev/null 2>&1; \
else \
/etc/init.d/cubicweb reload > /dev/null 2>&1; \
fi; \
endscript
}