gui: Add missing 'Close' button on remote devices' files (#5232)

gui/default/syncthing/transfer/remoteNeededFilesModalView.html

@@ -42,4 +42,9 @@
       </div>
     </div>
   </div>
+  <div class="modal-footer">
+    <button type="button" class="btn btn-default btn-sm" data-dismiss="modal">
+      <span class="fas fa-times"></span>&nbsp;<span translate>Close</span>
+    </button>
+  </div>
 </modal>