MaxScale detects an erroneous runtime change but may still use it

MaxScale validates runtime changes and rejects values that are wrong. However, if two values are dependent on each other (e.g. one must be smaller than the other), that dependency is checked only when the assignments to the variables already have been made.

If the dependency does not hold, a warning is logged to the MaxScale log file, an error is returned to the user of maxctrl and the new config is not saved, but the values are still used.

MaxScale should make all validations before any configuration parameters have been modified.