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

...mproved loading and checks #189
really? take a look at https://github.com/laterpay/laterpay-wordpress-plugin/blob/master/laterpay/library/laterpay/LaterPay/Controller/Post/Content.php#L321
please be careful when remove 'not required' params.
this client was ported from python client(also laterpay, not vendor) and we have task to make place it separately