Adjust class for mobile has the problem of double small bells (#20236)

* Adjust class for mobile has the problem of double small bells

* Update templates/base/head_navbar.tmpl

Co-authored-by: Gusted <[email protected]>

Co-authored-by: Gusted <[email protected]>

Author: tyroneyeh

templates/base/head_navbar.tmpl

@@ -114,7 +114,7 @@
 				</div>
 			</div>
 
-			<a href="{{AppSubUrl}}/notifications" class="item tooltip not-mobile" data-content='{{.locale.Tr "notifications"}}'>
+			<a href="{{AppSubUrl}}/notifications" class="m-4 text black tooltip not-mobile" data-content='{{.locale.Tr "notifications"}}'>
 				<span class="text">
 					<span class="fitted">{{svg "octicon-bell"}}</span>
 					<span class="ui red label {{if not $notificationUnreadCount}}hidden{{end}} notification_count">