[mangasee] changed website template (manga-download#1974)

[mangasee] changed website template (manga-download#1974)

fixes magicScroll when no gap between images (manga-download#1957)

[Line Webtoon] Fix ageGate error (manga-download#1767) (manga-downloa…

…d#1768)

[mangahub] migrated to new API (manga-download#1033)

improved GraphQL queries
updated image CDN

added support for quit hotkey on macOS (manga-download#995)

* add keybinding for CMD + Q for macOS

* only add quit menu entry for macOS

* code cleanup

changed update URL in client configuration

changed default development version info

updated to electron 7.1.9 (manga-download#951)

* updated to electron 7.1.9

* fixed mime type detection for custom protocol handlers

prevent promise from uncaught rejection error inside save chapter method