Fix commenting on deleted post (#7095)

webapp/components/create_comment/index.js

@@ -0,0 +1,16 @@
+// Copyright (c) 2017 Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+import {connect} from 'react-redux';
+
+import CreateComment from './create_comment.jsx';
+
+function mapStateToProps(state, ownProps) {
+    const err = state.requests.posts.createPost.error || {};
+    return {
+        ...ownProps,
+        createPostErrorId: err.server_error_id
+    };
+}
+
+export default connect(mapStateToProps)(CreateComment);