devel/electron42: Update to 42.9.3
Changelog:
- https://github.com/electron/electron/releases/tag/v42.9.1
- https://github.com/electron/electron/releases/tag/v42.9.2
- https://github.com/electron/electron/releases/tag/v42.9.3
Reported by: GitHub (watch releases)
(cherry picked from commit 49ce10da799eaff13ee9978a99b3d11b0daf3722)