Fix PDOStatement::execute parameter error in specific scenarios

Array to string conversion occurs when the PDOStatement::execute parameter is empty in a specific scenario.

releases 2.0.4

fix longxinH#17

fix segmentation fault

longxinH#16

release 2.0.2

fix longxinH#9

fix zts segment error

longxinH#8 php.ini can display with interval and depth configuration

php.ini can display with interval and depth configuration

longxinH#8 php.ini can display with interval and depth configuration

php.ini can display with interval and depth configuration

longxinH#4 fix for PHP 7.2

fix mysqli_query

Update README.md