Fixing issue with error conversion.
Fixing issue with error conversion.

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