Add optional colon.

config/initializers/1_settings.rb

@@ -176,7 +176,8 @@ Settings.gitlab['signup_enabled'] ||= true if Settings.gitlab['signup_enabled'].
 Settings.gitlab['signin_enabled'] ||= true if Settings.gitlab['signin_enabled'].nil?
 Settings.gitlab['restricted_visibility_levels'] = Settings.send(:verify_constant_array, Gitlab::VisibilityLevel, Settings.gitlab['restricted_visibility_levels'], [])
 Settings.gitlab['username_changing_enabled'] = true if Settings.gitlab['username_changing_enabled'].nil?
-Settings.gitlab['issue_closing_pattern'] = '((?:[Cc]los(?:e[sd]?|ing)|[Ff]ix(?:e[sd]|ing)?|[Rr]esolv(?:e[sd]?|ing)) +(?:(?:issues? +)?%{issue_ref}(?:(?:, *| +and +)?)|([A-Z][A-Z0-9_]+-\d+))+)' if Settings.gitlab['issue_closing_pattern'].nil?
+Settings.gitlab['issue_closing_pattern'] = '((?:[Cc]los(?:e[sd]?|ing)|[Ff]ix(?:e[sd]|ing)?|[Rr]esolv(?:e[sd]?|ing))(:?) +(?:(?:issues? +)?%{issue_ref}(?:(?:, *| +and +)?)|([A-Z][A-Z0-9_]+-\d+))+)' if Settings.gitlab['issue_closing_pattern'].nil?
+puts Settings.gitlab['issue_closing_pattern']
 Settings.gitlab['default_projects_features'] ||= {}
 Settings.gitlab['webhook_timeout'] ||= 10
 Settings.gitlab['max_attachment_size'] ||= 10