Remove no longer used HeaderController

Change-type: patch

lib/gui/app/app.js

@@ -40,7 +40,6 @@ const settings = require('./models/settings')
 const windowProgress = require('./os/window-progress')
 const analytics = require('./modules/analytics')
 const availableDrives = require('./models/available-drives')
-const selectionState = require('./models/selection-state')
 const driveScanner = require('./modules/drive-scanner')
 const osDialog = require('./os/dialog')
 const exceptionReporter = require('./modules/exception-reporter')
@@ -411,40 +410,6 @@ app.config(($locationProvider) => {
   })
 })
 
-app.controller('HeaderController', function (OSOpenExternalService) {
-  /**
-   * @summary Open help page
-   * @function
-   * @public
-   *
-   * @description
-   * This application will open either the image's support url, declared
-   * in the archive `manifest.json`, or the default Etcher help page.
-   *
-   * @example
-   * HeaderController.openHelpPage();
-   */
-  this.openHelpPage = () => {
-    const DEFAULT_SUPPORT_URL = 'https://github.com/balena-io/etcher/blob/master/SUPPORT.md'
-    const supportUrl = selectionState.getImageSupportUrl() || DEFAULT_SUPPORT_URL
-    OSOpenExternalService.open(supportUrl)
-  }
-
-  /**
-   * @summary Whether to show the help link
-   * @function
-   * @public
-   *
-   * @returns {Boolean}
-   *
-   * @example
-   * HeaderController.shouldShowHelp()
-   */
-  this.shouldShowHelp = () => {
-    return !settings.get('disableExternalLinks')
-  }
-})
-
 app.controller('StateController', function ($rootScope, $scope) {
   const unregisterStateChange = $rootScope.$on('$stateChangeSuccess', (event, toState, toParams, fromState) => {
     this.previousName = fromState.name