This could actually change the behaviour here (could, because I don't
know if we can hit this special case) but this should hopefully the
correct way of doing this.

There's some detailed explanation of the difference here:
https://doc.qt.io/qt-5/qstring.html#arg-14

> This is the same as str.arg(a1).arg(a2), except that the strings
> a1 and a2 are replaced in one pass. This can make a difference if
> a1 contains e.g. %1:

```
QString str;
str = "%1 %2";

str.arg("%1f", "Hello");        // returns "%1f Hello"
str.arg("%1f").arg("Hello");    // returns "Hellof %2"
```

Suggested-by:

Clazy: Use multi-arg instead