Fetch only master branch of the registry index
Fetch only master branch of the registry index

Should close #4016

tsurai/cargo,achanda/cargo,rustyhorde/cargo,tsurai/cargo,vojtechkral/cargo,tshepang/cargo,rustyhorde/cargo,vojtechkral/cargo,achanda/cargo,vojtechkral/cargo,tshepang/cargo,tshepang/cargo,rust-lang/cargo,nipunn1313/cargo,tsurai/cargo,eminence/cargo,vojtechkral/cargo,tsurai/cargo,eminence/cargo,durka/cargo,tshepang/cargo,durka/cargo,tsurai/cargo,eminence/cargo,nipunn1313/cargo,eminence/cargo,rustyhorde/cargo,achanda/cargo,rustyhorde/cargo,durka/cargo,achanda/cargo,rust-lang/cargo,nipunn1313/cargo,durka/cargo,rust-lang/cargo,nipunn1313/cargo,rust-lang/cargo