[BUG] Switch from about to home crashes

[mmebsout]

When using the Datacube application

• open the app in the home page
• click on the slider's image to produce a spectrum
• click on the menu icon (≡)
• click on the "about" page
• click on the "home" page
• about stays selected in the menu, a blank page is displayed and an error is showing in the console

core.js:1449 ERROR Error: Uncaught (in promise): Error: No DOM element with id 'graphDiv' exists on the page.
Error: No DOM element with id 'graphDiv' exists on the page.
    at Object.getGraphDiv (dom.js:29)
    at Object.addTraces (plot_api.js:1099)
    at SafeSubscriber.eval [as _next] (spectre.component.ts:156)
    at SafeSubscriber.__tryOrSetError (Subscriber.js:252)
    at SafeSubscriber.next (Subscriber.js:192)
    at Subscriber._next (Subscriber.js:131)
    at Subscriber.next (Subscriber.js:95)
    at FinallySubscriber.Subscriber._next (Subscriber.js:131)
    at FinallySubscriber.Subscriber.next (Subscriber.js:95)
    at CatchSubscriber.Subscriber._next (Subscriber.js:131)
    at resolvePromise (zone.js:831)
    at resolvePromise (zone.js:788)
    at eval (zone.js:892)
    at ZoneDelegate.invokeTask (zone.js:423)
    at Object.onInvokeTask (core.js:4751)
    at ZoneDelegate.invokeTask (zone.js:422)
    at Zone.runTask (zone.js:195)
    at drainMicroTaskQueue (zone.js:601)
    at ZoneTask.invokeTask [as invoke] (zone.js:502)
    at invokeTask (zone.js:1744)