Doc: clarify that REASSIGN OWNED doesn't handle default privileges.

It doesn't touch regular privileges either, but only the latter was
explicitly stated.

Discussion: https://postgr.es/m/155348282848.9808.12629518043813943231@wrigleys.postgresql.org

doc/src/sgml/ref/drop_owned.sgml

@@ -32,7 +32,7 @@ DROP OWNED BY { <replaceable class="parameter">name</replaceable> | CURRENT_USER
    <command>DROP OWNED</command> drops all the objects within the current
    database that are owned by one of the specified roles. Any
    privileges granted to the given roles on objects in the current
-   database and on shared objects (databases, tablespaces) will also be
+   database or on shared objects (databases, tablespaces) will also be
    revoked.
   </para>
  </refsect1>

doc/src/sgml/ref/reassign_owned.sgml

@@ -88,9 +88,11 @@ REASSIGN OWNED BY { <replaceable class="parameter">old_role</replaceable> | CURR
 
   <para>
    The <command>REASSIGN OWNED</command> command does not affect any
-   privileges granted to the <replaceable class="parameter">old_roles</replaceable> for
-   objects that are not owned by them.  Use <command>DROP OWNED</command> to
-   revoke such privileges.
+   privileges granted to
+   the <replaceable class="parameter">old_roles</replaceable> on objects
+   that are not owned by them.  Likewise, it does not affect default
+   privileges created with <command>ALTER DEFAULT PRIVILEGES</command>.
+   Use <command>DROP OWNED</command> to revoke such privileges.
   </para>
 
   <para>