Unnecessary db connect - function phpbb_bootstrap_enabled_exts

Function phpbb_bootstrap_enabled_exts() creates a unnecessary new db connection on every page hit.
@ https://github.com/phpbb/phpbb/blob/develop-ascraeus/phpBB/includes/functions_container.php#L67
The SQL query will also never displayed at the "sql debug" page.

It comes from the file common.php @ "// Set up container" https://github.com/phpbb/phpbb/blob/develop-ascraeus/phpBB/common.php#L94
before the standard db connection takes over.

similar to ~ https://tracker.phpbb.com/browse/PHPBB3-12420