Auto merge of #8212 - kornelski:testfix, r=alexcrichton
Auto merge of #8212 - kornelski:testfix, r=alexcrichton

Avoid testing git-specific error messages

#8166

eminence/cargo,eminence/cargo,nipunn1313/cargo,tshepang/cargo,rust-lang/cargo,rustyhorde/cargo,tsurai/cargo,rustyhorde/cargo,tshepang/cargo,tsurai/cargo,rust-lang/cargo,eminence/cargo,rust-lang/cargo,eminence/cargo,nipunn1313/cargo,rustyhorde/cargo,rust-lang/cargo,tsurai/cargo,tsurai/cargo,tshepang/cargo,nipunn1313/cargo,rustyhorde/cargo,tshepang/cargo,nipunn1313/cargo,tsurai/cargo