Fixed Web.get_page_info() - use contest.problem_mappings instead of contest.problems.
Fixed Web.get_page_info() - use contest.problem_mappings instead of contest.problems.

zielmicha/satori,zielmicha/satori,zielmicha/satori,zielmicha/satori,zielmicha/satori,zielmicha/satori,zielmicha/satori