The quickstart image needs changing how it does config upgrades, so instead of giving stellar-core a json file for the config to upgrade to, it gives it xdr.
However, stellar-core is being updated to remove the json dependency and will just accept xdr.
The stellar-core command we started using in 513 already supports both xdr and json, so we can switch at any point but need to switch before the v20 release of stellar-core.
The quickstart image needs changing how it does config upgrades, so instead of giving stellar-core a json file for the config to upgrade to, it gives it xdr.
In https://github.com/stellar/quickstart/pull/513 we added config upgrades using the json format.
However, stellar-core is being updated to remove the json dependency and will just accept xdr.
The stellar-core command we started using in 513 already supports both xdr and json, so we can switch at any point but need to switch before the v20 release of stellar-core.
cc @sisuresh @anupsdf