Fixup one last place where the AD code runs before the resolver is set up.

Also note: REQUIRE does not do what the original author of this code
intended. In an rcNG script REQUIRE X means that X must run before
the script that has the REQUIRE line runs.

You want ix-nssswitch to run, then nsswitch.
You can do this be either modifying nsswitch to REQUIRE ix-nssswitch
or by having ix-nsswitch BEFORE nsswitch.  We choose the latter as it
avoids a diff to stock FreeBSD.

Ticket: #7203