Pulseaudio: ignoring Master

Hello!
According to Fixing Volume Controls on the Asus ZenBook 3 (UX390UA) in Ubuntu 16.04, I need to change /usr/share/pulseaudio/alsa-mixer/paths/analog-output.conf.common to add this:

[Element Master]
switch = mute
volume = ignore

Can anybody point me in the right direction? Thank you!