Change-value: Allow regex old_value input

Description of the feature request

Allow using a regex for the old_value input in the change-value step.

Use case / for what or how I would use it

In one of the configuration files I need to replace a value, part of which varies.

Hi @frank!

Thanks for raising this thread, but the mentioned Change value step is a community created one, we do not maintain it. You are more than welcome to send a Pull Request for this change though!