Fix typos in dind-rootless sed expressions

[tianon]

Verified properly this time:

$ cat DockerfileFROM docker:dind-rootlessUSER rootRUN set -eux; \	sed -i -e 's/^rootless:x:1000:1000:/rootless:x:1234:5678:/' /etc/passwd; \	sed -i -e 's/^rootless:x:1000:/rootless:x:5678:/' /etc/group; \	chown -R rootless ~rootlessUSER rootless
$ docker buildx build --pull --tag tianon/dind1234 ....#6 exporting to image#6 exporting layers done#6 writing image sha256:114395aef97f155e9d229b3b2328e2149ae689b18f115cb6e3900ed469c7fdad done#6 naming to docker.io/tianon/dind1234 done#6 DONE 0.0s
$ docker run -dit --rm --name dind --privileged tianon/dind1234508c64a236d9ef97f6e533128ab1ea16928f79f354286d45483b96039094cc41
$ docker logs --tail=2 dindINFO[2025-03-03T20:55:39.874459873Z] API listen on /run/user/1234/docker.sock INFO[2025-03-03T20:55:39.874496567Z] API listen on [::]:2376 
$ docker exec -it dind docker-entrypoint.sh docker run --rm hello-worldUnable to find image 'hello-world:latest' locallylatest: Pulling from library/hello-worlde6590344b1a5: Pull complete Digest: sha256:bfbb0cc14f13f9ed1ae86abc2b9f11181dc50d779807ed3a3c5e55a6936dbdd5Status: Downloaded newer image for hello-world:latestHello from Docker!This message shows that your installation appears to be working correctly.To generate this message, Docker took the following steps: 1. The Docker client contacted the Docker daemon. 2. The Docker daemon pulled the "hello-world" image from the Docker Hub. (amd64) 3. The Docker daemon created a new container from that image which runs the executable that produces the output you are currently reading. 4. The Docker daemon streamed that output to the Docker client, which sent it to your terminal.To try something more ambitious, you can run an Ubuntu container with: $ docker run -it ubuntu bashShare images, automate workflows, and more with a free Docker ID: https://hub.docker.com/For more examples and ideas, visit: https://docs.docker.com/get-started/
$ docker top dind o uid,comm,pidUID COMMAND PID1234 rootlesskit 1129431234 exe 1130771234 vpnkit 1130931234 docker-init 1131071234 dockerd 1131111234 containerd 113128

Follow-up to #2546
Updates docker-library/docker#528

[imthosea]

That was fast