Auto merge of #5002 - lzutao:fmt-fallout, r=flip1995
Auto merge of #5002 - lzutao:fmt-fallout, r=flip1995

build: Use rustfmt from lastest nightly that contains it

changelog: none

graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,aidancully/rust,graydon/rust,graydon/rust,graydon/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust