Yeah that threw me for a loop too, I think it's because Hangouts isn't configure...

ams6110 · on July 28, 2015

Messaging on my Moto G (Android 4.4.4) does not have this setting.

Edit: Messaging (default app) doesn't have this setting, but Messenger does. I tried Hangouts for awhile but didn't like it.

gcb0 · on July 28, 2015

nobody does. but Google is trying hard to make you use it by deprecating the gvoice app.

now if you want to make calls from your gvoice number, you must use hangouts.

funny how they think forcing newer apps is the solution to the g+fiasco

thisisit · on July 28, 2015

Messaging on Moto G2 (Lollipop) does have this setting under MMS. Disabled it from there.