Fix null byte sanitisation

[smadeja]

Trying to sanitise input containing both invalid UTF-8 characters and null bytes will currently raise ArgumentError: invalid byte sequence in UTF-8 when the newly introduced sanitize_null_bytes option is set to true. The reason for that is that the optional null byte sanitisation happens before forcing UTF-8 encoding. This fixes that by making sure character sanitisation is performed first in both the default strategies

[amitsaxena]

@whitequark do you follow some release schedule or can we possibly have a newer version of the gem released with this fix?

[whitequark]

No schedule. I'll make a release.

[whitequark]

1.9.1

[amitsaxena]

Thanks a lot @whitequark! ⭐