Code review comment for lp://qastaging/~mabkenar/ubuntu-keyboard/add-persian-layout

I've just retested this on a clean Zesty VM and that key is rendered without issues, so I think it's one of the extra fonts installed on my personal system incorrectly claiming it can render this key when it can't (and so not allowing it to fallback to something that can). As such I think this branch is good to go :)