[4.0] Fix SQL error when updating from 3.10 (#33820)

* Fix SQL error on update from 3.10

* Fix wrong names quoting for postgresql

* Revert "Fix SQL error on update from 3.10"

This reverts commit de7ddb1.

* Revert previous change in 4.0.0-2018-06-03.sql and use IF EXISTS for DROP TABLE instead

Author: richard67

administrator/components/com_admin/sql/updates/mysql/4.0.0-2021-05-04.sql

@@ -1,2 +1,2 @@
 DELETE FROM `#__extensions` WHERE `name` = 'com_csp' and `type` = 'component' and `element` = 'com_csp';
-DROP TABLE `#__csp`;
+DROP TABLE IF EXISTS `#__csp`;

administrator/components/com_admin/sql/updates/postgresql/4.0.0-2021-05-04.sql

@@ -1,2 +1,2 @@
-DELETE FROM `#__extensions` WHERE `name` = 'com_csp' and `type` = 'component' and `element` = 'com_csp';
-DROP TABLE `#__csp`;
+DELETE FROM "#__extensions" WHERE "name" = 'com_csp' and "type" = 'component' and "element" = 'com_csp';
+DROP TABLE IF EXISTS "#__csp";