Fixed $before_needle argument of strrchr() description

[mumumu]

New parameter $before_needle outputs result based on the last occurances of needle.

$ sapi/cli/php --version | head -n 1
PHP 8.4.0-dev (cli) (built: Aug 30 2023 22:08:33) (NTS)

$ sapi/cli/php -r '$text = "Line 1:Line 2:Line 3"; var_dump(strrchr($text, ":", false));'
string(7) ":Line 3"

$ sapi/cli/php -r '$text = "Line 1:Line 2:Line 3"; var_dump(strrchr($text, ":", true));'
string(13) "Line 1:Line 2"

[TimWolla]

LGTM except for that remark.