Auto merge of #41978 - alexcrichton:update-cargo, r=Mark-Simulacrum

bors · bors · commit 386b0b9d3927 · 2017-05-14T16:16:17.000Z
Update the Cargo submodule

Brings some nice updates like faster index clones/updates, retries on 500 from
crates.io, etc.
diff --git a/src/tools/cargo b/src/tools/cargo
@@ -1 +1 @@
-Subproject commit cf17c9f7118f544ec304ed6f50d92b3759487123
+Subproject commit 13d92c64d0153d95dbabeb49b828bbbef4b1bb34
