Fix seteditraw classic save button (#6164)

Fixes https://github.com/roundcube/roundcubemail/issues/6154

plugins/managesieve/skins/classic/templates/seteditraw.html

@@ -11,9 +11,11 @@
 <div id="filter-form" class="boxcontent">
 <roundcube:object name="filterseteditraw" />
 
-<p>
+<div id="footer">
+<div class="footerleft formbuttons">
 <roundcube:button command="plugin.managesieve-save" type="input" class="button mainaction" label="save" />
-</p>
+</div>
+</div>
 
 </form>
 </div>