Bumped libgit2 to libgit-next head

cjhoward92 · cjhoward92 · commit a6f43ecaabaa · 2017-10-10T12:28:47.000-07:00
diff --git a/vendor/libgit2 b/vendor/libgit2
@@ -1 +1 @@
-Subproject commit 3c1308d8c1afa74d5da76ff1d3b2106d352ed36f
+Subproject commit da12bb87a7d206d3c8dfdd0922d0c3c7009965ba
