Remove Untrack() from free() function
Remove Untrack() from free() function

https://github.com/libgit2/git2go/pull/257#discussion_r53443211

pks-t/git2go,ezwiebel/git2go,ezwiebel/git2go,pks-t/git2go,clns/git2go,libgit2/git2go,libgit2/git2go,clns/git2go,libgit2/git2go,ezwiebel/git2go,clns/git2go