Auto merge of #4024 - rsertelon:fix-4016-fetch-only-master, r=alexcrichton
authorbors <bors@rust-lang.org>
Wed, 10 May 2017 21:52:53 +0000 (21:52 +0000)
committerbors <bors@rust-lang.org>
Wed, 10 May 2017 21:52:53 +0000 (21:52 +0000)
Fetch only master branch of the registry index

Should close #4016


Trivial merge