message: fixed fallback image padding
diff: <div class="course-image-upload">
  <div class="course-image">
  <app-responsive-image *ngIf="this.courseImageData" [responsiveImageData]="this.courseImageData"></app-responsive-image>
  - <img *ngIf="!this.courseImageData" mat-card-image src="/assets/course-header-image.jpg">
  + <img *ngIf="!this.courseImageData" src="/assets/course-header-image.jpg">
  </div>
  <div>
  