apt update Error 404 Not Found

Question

sudo apt-get update
Hit:1 https://repo.skype.com/deb stable InRelease
Ign:2 https://www.dotdeb.org stable InRelease
Err:3 https://www.dotdeb.org stable Release
  404  Not Found [IP: 195.154.242.153 443]
Reading package lists... Done

How can i solve this? I don't need anymore dotdeb