Upgrade libgit2 to a3dc419.

arthurschreiber · arthurschreiber · commit 39a3fe030d87 · 2015-12-07T09:01:26.000+01:00
diff --git a/vendor/libgit2 b/vendor/libgit2
@@ -1 +1 @@
-Subproject commit a589f22a9441523327e4c987c5b5f5f857472067
+Subproject commit a3dc4190e77ff794109c3ff2fbcb3fa87e5f7c48
