Fix setting post_mortem mode
Fix setting post_mortem mode

webdev1001/byebug,icebreaker/byebug,scalp42/byebug,deivid-rodriguez/byebug,davidmowrer/in_class_projects_t2,davidmowrer/in_class_projects_t2,os97673/byebug,phusion/byebug,edward/byebug,scalp42/byebug,webdev1001/byebug,k0kubun/byebug,phusion/byebug,ozydingo/byebug,guilherme/byebug,icebreaker/byebug,yui-knk/byebug,deivid-rodriguez/byebug,miamiruby/byebug,guilherme/byebug,saisai/byebug,edward/byebug,miamiruby/byebug,guilherme/byebug,k0kubun/byebug,yui-knk/byebug,ozydingo/byebug,deivid-rodriguez/byebug,os97673/byebug,k0kubun/byebug,saisai/byebug,yui-knk/byebug,davidmowrer/in_class_projects_t2