MOBILE-2819 a11y: Fix image description read twice

Author: dpalou

src/addon/mod/data/fields/picture/component/addon-mod-data-field-picture.html

@@ -11,6 +11,6 @@
     <ion-input type="text" [formControlName]="'f_'+field.id" [placeholder]="field.name"></ion-input>
 </span>
 
-<span *ngIf="mode == 'list' && imageUrl" (click)="gotoEntry.emit(entryId)"><img [src]="imageUrl" [alt]="title" [title]="title" class="core-media-adapt-width list_picture" core-external-content/></span>
+<span *ngIf="mode == 'list' && imageUrl" (click)="gotoEntry.emit(entryId)"><img [src]="imageUrl" [alt]="title" class="core-media-adapt-width list_picture" core-external-content/></span>
 
-<img *ngIf="mode == 'show' && imageUrl" [src]="imageUrl" [alt]="title" [title]="title" class="core-media-adapt-width list_picture" [attr.width]="width" [attr.height]="height" core-external-content/>
+<img *ngIf="mode == 'show' && imageUrl" [src]="imageUrl" [alt]="title" class="core-media-adapt-width list_picture" [attr.width]="width" [attr.height]="height" core-external-content/>

src/core/course/components/module-completion/core-course-module-completion.html

@@ -1,3 +1,3 @@
 <a *ngIf="completion" (click)="completionClicked($event)">
-    <img [src]="completionImage" [alt]="completionDescription" [title]="completionDescription">
+    <img [src]="completionImage" [alt]="completionDescription">
 </a>