enable_dns_caching breaks the resolver

[mfeit-internet2]

enable_dns_caching changes /etc/nsswitch.conf from hosts: db files nisplus nis dns to hosts: resolve files dns myhostname.

The latter causes resolution times for the local hostname (which is in /etc/hosts) of about five seconds, which is long enough that pScheduler throws in the towel on it. The docs for systemd-resolved say it's supposed to synthesize a cache entry for the local host name, but I'm not seeing that.

I recommend hosts: files resolve files dns myhostname instead.

I suspect that this may be gumming up the startup of OpenSearch, because making the change above gets it to start after its other problems are resolved.