Bump libgit2 to fork of latest master

implausible · implausible · commit 2dc4f2db56b5 · 2019-06-25T16:04:39.000-07:00
diff --git a/vendor/libgit2 b/vendor/libgit2
@@ -1 +1 @@
-Subproject commit 97e4179a76b935a15589a44662ce54a0ce0f3026
+Subproject commit 0cfb5596ac1d0a0a88c3a449f885ee84ec4a8fb3
