Drop gateway.recover_after_nodes from default conf (#68000)
Drop gateway.recover_after_nodes from default conf (#68000)

The `gateway.recover_after_nodes` setting is one of the lucky few that
gets a mention in the default `elasticsearch.yml` config file. This
setting was deprecated in favour of `gateway.recover_after_data_nodes`
in #53646, but neither of these settings is really important enough to
warrant a place in the default config so this commit removes it.
GlenRSmith/elasticsearch,robin13/elasticsearch,robin13/elasticsearch,GlenRSmith/elasticsearch,robin13/elasticsearch,GlenRSmith/elasticsearch,GlenRSmith/elasticsearch,GlenRSmith/elasticsearch,robin13/elasticsearch,robin13/elasticsearch