It seems the "25_bli" file gets its executable bit reset after
updating/reinstalling the package. But I found it is installed with "noreplace"
```
%config(noreplace) %{_sysconfdir}/grub.d/25_bli
```
meaning a better workaround seems to be inserting `exit 0` at the beginning of
the script.
But of course, not a permanent solution. ;-)