How to fix buster installation problem (raspbian image release june 2019)

Tried to install a new system, using the raspbian buster image june 2019

first step would normally be:

sudo apt-get update
sudo apt-get -yq upgrade

however, I got an error:

E: Repository 'http://security.debian.org/debian-security buster/updates InRelease' changed its 'Suite' value from 'testing' to 'stable'
N: This must be accepted explicitly before updates for this repository can be applied. See apt-secure(8) manpage for details.

edit
FIX, NOT tested, but explained by somebody on tweakers.net here (dutch):

sudo apt update

and answer ‘y
reference here.
/edit

Why do you have a debian.org repo in Raspbian?

this is NOT the error message I got on Raspbian, but an identical one, copied from the reference.

My original solution (tested) was to run:

sudo apt-get update --allow-releaseinfo-change
sudo DEBIAN_FRONTEND=noninteractive apt-get -yq upgrade

but somebody on another forum pointed out there is an easier way.

edit
new Raspbian image (july 2019) has been released, download here
/edit