Number of Telegram Stars that must be paid for every incoming private message by non-contacts; 0- getOption("paid_message_star_count_max"). If positive, then allow_new_chats_from_unknown_users must be true. The current user will receive getOption("paid_message_earnings_per_mille") Telegram Stars for each 1000 Telegram Stars paid for message sending. Can be positive, only if getOption("can_enable_paid_messages") is true