detect checkpoint

[sooluh]

I added a detection when an Instagram account encounters checkpoint.
On line 139, instead of validating whether bloks.login_response exists or not, I reverted it back to its original state because the error has been handled above before everything runs, and when an error occurs, we throw an error.
And on line 140, I made the usage of pk consistent instead of pk_id.

[elijah-wright]

alr, looks good to me