Auto merge of #4644 - dethoter:4620, r=matklad
authorbors <bors@rust-lang.org>
Thu, 26 Oct 2017 05:17:36 +0000 (05:17 +0000)
committerbors <bors@rust-lang.org>
Thu, 26 Oct 2017 05:17:36 +0000 (05:17 +0000)
Fix documentation for package.readme option.

Fix for #4620.


Trivial merge