[MlMt] "reply to sender" button doing reply-to-all

[Eric Sharakan]

Hi, I have the "Reply/Reply All/Forward" button configured on my 
toolbar, and just realized that the "reply" button is actually doing 
"reply all".

This is rather embarrassing, as I tend to harp on folks who 
inappropriately use "reply all", only to find I might have been doing so 
myself unexpectedly. :-(

Catalina 10.15.2/MM 5676.

-Eric