Improve member adding and excluding flow

Allow to exclude a member

Send emails to the member when it's excluded

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

js/src/components/Comment/CommentTree.vue

@@ -106,6 +106,7 @@ export default class CommentTree extends Vue {
 
   async createCommentForEvent(comment: IComment) {
     try {
+      if (!comment.actor) return;
       await this.$apollo.mutate({
         mutation: CREATE_COMMENT_FROM_EVENT,
         variables: {