acme.sh dnsapi/dns_edgedns.sh invokes iconv(1) which is not provided by
OpenBSD in the base system. Adding the libiconv package provides this tool.
This should also help address acmesh-official/acme.sh#4350, albeit indirectly:
it looks like that PR cannot be merged because the OpenBSD test fails despite
the PR not actually changing anything having to do with iconv. That is, I
suspect that the test for OpenBSD failed (or would have failed, had it been
run?) prior to that PR being issued.
(This was previously submitted as
https://github.com/acmesh-official/acmetest/pull/28 )
With nsupdate the rule seems to be: filenames need to be wrapped
in double quotes, while all other options must not use double quotes.
Hence there is no way to resolve the shellcheck offense, because
the key requires quotes, but the other options must not use quotes.