Fix nil values case in first migration
Fix nil values case in first migration

jbox-web/redmine_git_hosting,stanclai/redmine_git_hosting,stanclai/redmine_git_hosting,stanclai/redmine_git_hosting,stanclai/redmine_git_hosting,stanclai/redmine_git_hosting,jbox-web/redmine_git_hosting,jbox-web/redmine_git_hosting,jbox-web/redmine_git_hosting