cubicweb #1524163 configuration values should be kept during option migration [rejected]

All the cmd_option_* methods should take care of the current configuration values.

CubicWeb has already an API to reorganize the configuration entries in all-in-one.conf but we have to restore specific values by hand at the moment.

For example, when we moved the port option in recent migration, we lose the filled port number.

prioritynormal
typebug
done in<not specified>
load0.000
load left0.000
closed by<not specified>