Silence gcc-10-fanalyzer false positive
requested to merge 2701-gcc-10-fanalyzer-reports-dereference-of-null-label-in-lib-dns-name-c-1167-v9_16 into v9_16
If 'state == ft_ordinary' then 'label' can't be NULL. Add INSIST to reflect this.
(cherry picked from commit 29f1c1e6)
Closes #2701 (closed)