sudo apt-get update警告Duplicate sources.list entry

在一个虚拟机运行apt-get update警告

W: Duplicate sources.list entry http://archive.canonical.com/ubuntu/ precise/partner amd64 Packages
 (/var/lib/apt/lists/archive.canonical.com_ubuntu_dists_precise_partner_binary-amd64_Packages)
W: Duplicate sources.list entry http://archive.canonical.com/ubuntu/ precise/partner i386 Packages 
(/var/lib/apt/lists/archive.canonical.com_ubuntu_dists_precise_partner_binary-i386_Packages)

参考： https://blog.csdn.net/weixin_34087301/article/details/94498327