Rugged cuts diff headers in the middle of multi-byte characters
https://github.com/libgit2/rugged/issues/716
This causes an exception like RangeError: X..Y out of range to be sent to Sentry when highlighting inline diff ranges. We rescue from the error in https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/17262, which is safe (as described in that issue) because we will have the 'correct' encoding displayed, we just can't add the inline diff highlighting.
Once a version of Rugged with the fix is released, we should update to that version and remove the exception-catch-and-Sentry-report we have.