Use `list.id` for `:key`

app/views/shared/boards/_show.html.haml

@@ -27,7 +27,7 @@
       ":issue-link-base" => "issueLinkBase",
       ":root-path" => "rootPath",
       ":board-id" => "boardId",
-      ":key" => "_uid" }
+      ":key" => "list.id" }
   = render "shared/boards/components/sidebar", group: group
   - if @project
     %board-add-issues-modal{ "new-issue-path" => new_project_issue_path(@project),