Specify the change about adding CORS same-origin as breaking change, because it breakes the app when you were not passing the CORS header in the config

[vitaliypogoretskyy-art]

Breaking changes were added in context of df073c5#r188029710 without specifying it's a breaking change, moreover in a patch version!

While reasonable, they break the app behavior if CORS header is not passed, which was our case and probably not only ours.

@UlisesGascon