insert comment with username null

[najiboulhouch]

Hi @SaiUpadhyayula,

New comment was added with Null username, can you fix this in your code ?

My proposition was to add username from authservice that was stored in local storage.

ViewPostComponent file :

before :

      this.commentPayload = {
        text : '',
        postId : this.postId,
      };

after :

      this.commentPayload = {
        text : '',
        postId : this.postId,
        username : authService.getUsername(),
      };