Auto merge of #4281 - alexcrichton:backport3, r=alexcrichton
authorbors <bors@rust-lang.org>
Thu, 13 Jul 2017 13:56:56 +0000 (13:56 +0000)
committerbors <bors@rust-lang.org>
Thu, 13 Jul 2017 13:56:56 +0000 (13:56 +0000)
[beta] Don't push empty paths in LD_LIBRARY_PATH

Fixes #4277.


Trivial merge