Sorry, I would have fixed all the images but I was on mobile and got called away. Anyway, looks like you figured it out.
Personally, I wouldn't worry too much about that chip. It doesn't look big enough to worry about, and I've seen tanks with much deeper chips that were never an issue. That said, it really comes down to your appetite for risk.
You said you just noticed it though. Is this a new tank or did that chip recently happen?