[에러해결] N: Ignoring file 'ros-latest.list' in directory '/etc/apt/sources.list.d/' as it has an invalid filename extension

cd /etc/apt/sources.list.d
sudo rm ros-latest.list.save
sudo rm ros-latest.list
cd
sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'
sudo apt-get update
sudo apt-get upgrade