I've seen many poople saying to overlook it. But that crack seems large. I personally would replace the housing just to be safe. Like to a 7cm housing (16g housing). ...and you'll have a poor-man's 16g.

That's what I'm doing with mine.
I'll probably sell my stock housing, but that could be months from now. I'm pretty sure mine's in very good condition. (Not even 79,000 miles on it.)
Who knows if it'll crack further under heat and vibrations from hitting potholes. Better safe than sorry.