Replace outer padding of issue boards switcher with margin

app/assets/stylesheets/pages/boards.scss

@@ -722,10 +722,6 @@
   }
 }
 
-.boards-switcher {
-  padding-right: 10px;
-}
-
 .board-milestone-list {
   > li {
     padding-left: 0;

ee/app/assets/javascripts/boards/components/boards_selector.vue

@@ -195,7 +195,7 @@ export default {
 </script>
 
 <template>
-  <div class="boards-switcher js-boards-selector">
+  <div class="boards-switcher js-boards-selector append-right-10">
     <span class="boards-selector-wrapper js-boards-selector-wrapper">
       <div class="dropdown">
         <button