Fixup regression introduced in commit 1bbcd91b2ef0738709f7d95
("spacefm: sudo and gksu fixes#15758 and license update").
A missing </filename> end tag caused this:
$ nixos-rebuild build
...
options-db.xml:4402: parser error : Opening and ending tag mismatch: filename line 4401 and para
</para><para><emphasis>Type:</emphasis> boolean</para><para><emphasis>Default:</
^
options-db.xml:4406: parser error : Opening and ending tag mismatch: filename line 4401 and listitem
</filename></member></simplelist></listitem></varlistentry><varliste
^
options-db.xml:4406: parser error : Opening and ending tag mismatch: para line 4401 and varlistentry
</filename></member></simplelist></listitem></varlistentry><varliste
^
options-db.xml:28430: parser error : Opening and ending tag mismatch: listitem line 4401 and variablelist
</filename></member></simplelist></listitem></varlistentry></variablelist
^
options-db.xml:28432: parser error : Premature end of data in tag varlistentry line 4401
