Until now sysrescue-configuration.lua always ensured the default values were
in the effective JSON config because there was no way to remove them. Now the
lua script is improved to allow full config merging, including a delete function.
This could lead to the user accidently removing a value. The scripts did not
expect this and accessed non existing keys, leading to an exception.
This is fixed with this commit.
This allows to add additional CAs as trust anchors via the root key
"ca-trust" in the YAML config files.
Why is this helpful and can't be done for example with SRMs?
After the CA files are copied, "update-ca-trust" must be called. This
updates *all* ca trust files. This means your SRM will override all
trust files with the ones used when creating the SRM.
When you then use the SRM with a newer version of SystemRescue, you will
still use the old ca trust files from when the SRM was built.
