create_function deprecated

When define WP_DEBUG, get lots of messages like:

[15-Jun-2020 15:22:08 UTC] PHP Deprecated: Function create_function() is deprecated in /blah/plugins/bwp-recaptcha/bwp-recaptcha.php on line 40

Changed line 40 to:

`add_filter(‘bwp_capt_init_priority’, function() { return 9; });