[FIX] Problem enabling poll participation by anonymous users

Anonymous users aren't able to vote in polls even when tiki_p_vote_poll is assigned to Anonymous group. So we need to fix this issue.

Related links:

• https://dev.tiki.org/item1172-Problem-enabling-poll-participation-by-anonymous-users
• https://avan.tech/item69297-Problem-enabling-poll-participation-by-anonymous-users