From PostgreSQL 13, the "CREATE EXTENSION ... FROM" syntax is no longer
available. It's unlikely at this point that someone will find themselves
with a PostgreSQL 13 database and the legacy repmgr schema, but we'll
cover all bases just in case.
"repmgr daemon" can be interpreted to mean the commands affect the local
daemon process only. Rename the commands which affect the entire cluster
to "repmgr service ...".
The "repmgr daemon ..." form of the affected commands is retained for backwards
compatibility.
