python-tgcaptcha2: reusable captchas

If an attacker stores a captcha and its hidden value, they can reuse that same captcha an unlimited amount of time for as long as it's valid.

Version-Release number of selected component (if applicable): python-tgccaptcha2-0.2.0-1

How reproducible: Consistent

Steps to Reproduce:
1. Get one captcha value and store the hidden value and solves answer
2. Submit those values twice

Actual results: Both times are accepted.

Expected results: The second time should be refused.