The Version 4.4 of the Theme Support Plugin has been posted to the WordPress.org plugin repository, so you should update to that version.
As a reminder, here are the chanages for 4.4:
= Version 4.4 =
* Updated: Major refactoring of Customizer Interface Code
* Tweak: Improved menu locations of some Customizer Options
* Added: Some transition features for version 5.0
* Added: alignment option to #wrapper
* Fixed: default alignment for #wrapper is center
* Added: L/R % Padding to Wrapper, Container, Header, Footer
* Updated: Gallery Post Format code
* Tweak: Fixed issues with Site Title on Primary Menu: color wasn’t inherit by default, double instance on default menu
* Added: New “Absolutely” subtheme – uses Align Wide + L/R % padding to get full width layout
* Tweak: Added new “Clear One-Step Layout Settings”
* Fix: Added missing ‘Full text for 1st “n” Posts’ option to Customizer. Was in Legacy before.