removed wrong filter for buy_post and token_hook. Removed unsafe code, i...

...mproved loading and checks #189
the params are set on https://github.com/laterpay/laterpay-wordpress-plugin/blob/feature/189_buy_post_and_token_hook_wrong_filter/laterpay/library/laterpay/LaterPay/Controller/Post/Content.php#L455 . we've at least to validate the given params somehow to aviod security-risks.