use storage instead of component state to store the zoom setting

preload.js

@@ -86,7 +86,7 @@ const localeMessages = ipc.sendSync('locale-data');
 window.updateZoomFactor = () => {
   const zoomFactor = window.getSettingValue('zoom-factor-setting') || 100;
   window.setZoomFactor(zoomFactor / 100);
-}
+};
 
 window.setZoomFactor = number => {
   webFrame.setZoomFactor(number);

ts/components/session/settings/SessionSettingListItem.tsx

@@ -142,7 +142,5 @@ export class SessionSettingListItem extends React.Component<Props, State> {
     this.setState({
       sliderValue: value,
     });
-
-    
   }
 }