Fix a printing crash when the printing window is closing.
Fix a printing crash when the printing window is closing.

tommymckinley/electron-sample-apps,tommymckinley/electron-sample-apps,synaptek/electron-sample-apps,EdZava/electron-sample-apps,moogDE/electron-sample-apps,bright-sparks/electron-sample-apps,vevedh/electron-sample-apps,moogDE/electron-sample-apps,synaptek/electron-sample-apps,EdZava/electron-sample-apps,EdZava/electron-sample-apps,synaptek/electron-sample-apps,tommymckinley/electron-sample-apps,vevedh/electron-sample-apps,bright-sparks/electron-sample-apps,vevedh/electron-sample-apps,moogDE/electron-sample-apps,bright-sparks/electron-sample-apps