Fix alt attrs for img in files_versions

Signed-off-by: julia.kirschenheuter <julia.kirschenheuter@nextcloud.com>

Author: JuliaKirschenheuter

apps/files_versions/src/templates/item.handlebars

@@ -1,7 +1,7 @@
 <li data-revision="{{id}}">
 	<div>
 		<div class="preview-container">
-			<img class="preview" src="{{previewUrl}}" width="44" height="44"/>
+			<img alt="" class="preview" src="{{previewUrl}}" width="44" height="44"/>
 		</div>
 		<div class="version-container">
 			<div>
@@ -16,7 +16,7 @@
 			{{/hasDetails}}
 		</div>
 		{{#canRevert}}
-			<a href="#" class="revertVersion" title="{{revertLabel}}"><img src="{{revertIconUrl}}" /></a>
+			<a href="#" class="revertVersion" title="{{revertLabel}}"><img alt="" src="{{revertIconUrl}}" /></a>
 		{{/canRevert}}
 	</div>
 </li>