doc: Improve indentation of SQL examples

Some of these were indented using 8 spaces whereas the rest uses 4
spaces.  Probably originally some difference in tab size.

doc/src/sgml/queries.sgml

@@ -1955,11 +1955,11 @@ WITH regional_sales AS (
     SELECT region, SUM(amount) AS total_sales
     FROM orders
     GROUP BY region
-     ), top_regions AS (
+), top_regions AS (
     SELECT region
     FROM regional_sales
     WHERE total_sales > (SELECT SUM(total_sales)/10 FROM regional_sales)
-     )
+)
 SELECT region,
        product,
        SUM(quantity) AS product_units,
@@ -2071,7 +2071,7 @@ WITH RECURSIVE included_parts(sub_part, part, quantity) AS (
     SELECT p.sub_part, p.part, p.quantity
     FROM included_parts pr, parts p
     WHERE p.part = pr.sub_part
-  )
+)
 SELECT sub_part, SUM(quantity) as total_quantity
 FROM included_parts
 GROUP BY sub_part
@@ -2295,7 +2295,7 @@ WITH RECURSIVE included_parts(sub_part, part) AS (
     SELECT p.sub_part, p.part
     FROM included_parts pr, parts p
     WHERE p.part = pr.sub_part
-  )
+)
 DELETE FROM parts
   WHERE part IN (SELECT part FROM included_parts);
 </programlisting>