JavaScript error when summoning Preferences while About window is frontmost

[ryandesign]

Steps to reproduce

1. open Image Shrinker 1.6.4
2. select "About Image Shrinker" from the Image Shrinker menu
3. select "Preferences" from the Image Shrinker menu

Result

A JavaScript error occurred in the main process

Uncaught Exception:
TypeError: Cannot read property 'webContents' of undefined
at click (/Volumes/Shared/Applications/Image Shrinker.app/Contents/Resources/app.asar/menu/mainmenu.js:32:35)
at MenuItem.click (electron/js2c/browser_init.js:69:1626)
at Object.l._executeCommand (electron/js2c/browser_init.js:77:2328)