Allow PATCH/DELETE w/o Prefer when no SELECT privs

PATCH/DELETE can now be done without adding Prefer return=minimal when
the user doesn't have SELECT privileges.

* Also fix PATCH wrong HTTP status code

test/fixtures/schema.sql

@@ -1753,3 +1753,9 @@ CREATE TABLE web_content (
 CREATE FUNCTION getallusers() RETURNS SETOF users AS $$
   SELECT * FROM test.users;
 $$ LANGUAGE sql;
+
+create table app_users (
+  id       integer    primary key,
+  email    text       unique not null,
+  password text       not null
+);