restore accidentially removed class

Author: denyskon

templates/repo/issue/labels/edit_delete_label.tmpl

@@ -30,7 +30,7 @@
 				</div>
 				<br>
 				<small class="desc">{{.locale.Tr "repo.issues.label_exclusive_desc" | Safe}}</small>
-				<div class="gt-ml-2 gt-mt-3 gt-hidden label-exclusive-warning">
+				<div class="desc gt-ml-2 gt-mt-3 gt-hidden label-exclusive-warning">
 					{{svg "octicon-alert"}} {{.locale.Tr "repo.issues.label_exclusive_warning" | Safe}}
 				</div>
 			</div>