OTTAWA — The federal justice minister says an upcoming bill will propose changes to restore mandatory minimum sentences for the possession and access of child pornography recently struck down by Canada’s top court.   In an interview, Justice Minister Sean Fraser said he supported mandatory minimum penalties for “heinous” crimes, namely those against children.   But he said many such laws were drafted broadly and unintentionally capture situations where they may be too harsh, leaving them vulnerable to constitutional challenges.   “There is a gap that exists today that I believe...