auxiliary processes in pg_stat_ssl

I just noticed that we list auxiliary processes in pg_stat_ssl:

55432 13devel 28627=# select * from pg_stat_ssl ;
pid │ ssl │ version │ cipher │ bits │ compression │ client_dn │ client_serial │ issuer_dn
───────┼─────┼─────────┼────────────────────────┼──────┼─────────────┼───────────┼───────────────┼───────────
28618 │ f │ │ │ │ │ │ │
28620 │ f │ │ │ │ │ │ │
28627 │ t │ TLSv1.3 │ TLS_AES_256_GCM_SHA384 │ 256 │ f │ │ │
28616 │ f │ │ │ │ │ │ │
28615 │ f │ │ │ │ │ │ │
28617 │ f │ │ │ │ │ │ │
(6 filas)

55432 13devel 28627=# select pid, backend_type from pg_stat_activity ;
pid │ backend_type
───────┼──────────────────────────────
28618 │ autovacuum launcher
28620 │ logical replication launcher
28627 │ client backend
28616 │ background writer
28615 │ checkpointer
28617 │ walwriter
(6 filas)

But this seems pointless. Should we not hide those? Seems this only
happened as an unintended side-effect of fc70a4b0df38. It appears to me
that we should redefine that view to restrict backend_type that's
'client backend' (maybe include 'wal receiver'/'wal sender' also, not
sure.)

--
Álvaro Herrera http://www.twitter.com/alvherre