Bump libgit2 to c756448

carlosmn · carlosmn · commit 5af96de26892 · 2016-05-24T16:19:04.000+02:00
This includes a bug-fix in the tree updater.
diff --git a/vendor/libgit2 b/vendor/libgit2
@@ -1 +1 @@
-Subproject commit c91a1dc1d975aa32c58cfafbf1625dcbb0be7c3c
+Subproject commit c756448cefdf7369f30c45e9427ad5ba67e33483
