fix: text file delete button should not be visible when no file has been uploaded

Author: sergeleger

packages/studio-web/src/app/upload/upload.component.html

@@ -58,7 +58,7 @@ <h1 i18n="Title for text box" class="title">Text</h1>
               <!-- </div> -->
             </div>
           </div>
-          @if (studioService.textControl$.value !== null) {
+          @if (textFileUpload.value) {
             <div class="row">
               <div class="col-12 offset-xl-8 col-xl-4">
                 <button