Display attachments of review comment when comment content is blank (#23035) (#23046)

Backport #23035

Co-authored-by: sillyguodong <33891828+sillyguodong@users.noreply.github.com>

templates/repo/issue/view_content/comments.tmpl

@@ -399,7 +399,7 @@
 						{{end}}
 					</span>
 				</div>
-				{{if .Content}}
+				{{if or .Content .Attachments}}
 				<div class="timeline-item comment" id="{{.HashTag}}">
 					<div class="content comment-container">
 						<div class="ui top attached header comment-header df ac sb">