Update Cargo with a Windows 7 warning

alexcrichton · Mark-Simulacrum · commit 17a7bae777f0 · 2018-02-26T18:20:51.000-07:00
More info at rust-lang/cargo#5066
diff --git a/src/tools/cargo b/src/tools/cargo
@@ -1 +1 @@
-Subproject commit 8c93e089536467783957fec23b0f2627bb6ce357
+Subproject commit 96d8071da2800d871677d090c31b030d5b9682bc
