close dialog when clicking backdrop

empty @click.stop to allow clicking inside the dialog

app/assets/javascripts/vue_shared/components/popup_dialog.vue

@@ -52,10 +52,12 @@ export default {
     class="modal popup-dialog"
     role="dialog"
     tabindex="-1"
+    @click="close"
   >
     <div
       class="modal-dialog modal-md"
       role="document"
+      @click.stop
     >
       <div class="modal-content">
         <div class="modal-header">
@@ -101,10 +103,6 @@ export default {
       </div>
     </div>
   </div>
-
-  <div
-    class="modal-backdrop fade in"
-    @click="close"
-  />
+  <div class="modal-backdrop fade in" />
 </div>
 </template>