message: Perform more consistent null checks when traversing config
  (obsoletes
diff: @@ -32,9 +32,9 @@ export class WelcomeBannerComponent implements OnInit {
  this.title = config.application.welcomeBanner.title
  this.message = config.application.welcomeBanner.message
  }
  - this.showHackingInstructor = config.hackingInstructor?.isEnabled
  + this.showHackingInstructor = config?.hackingInstructor?.isEnabled
  // Don't allow to skip the tutorials when restrictToTutorialsFirst and showHackingInstructor are enabled
  - if (this.showHackingInstructor && config.challenges?.restrictToTutorialsFirst) {
  + if (this.showHackingInstructor && config?.challenges?.restrictToTutorialsFirst) {
  this.dialogRef.disableClose = true
  this.showDismissBtn = false
  }
  