Clarify the mechanism of prepared statements in MySQLi quickstart

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Provided by anonymous #33362 on PHDOE

git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@331330 c90b9560-bf6c-de11-be94-00142212c4b1
Whitespace fixes

Fix all outstanding strict whitespace errors flagged by the online editor

git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@331331 c90b9560-bf6c-de11-be94-00142212c4b1