Fix IndexOutOfBoundsException on FetchRemoteCatalogCommand

IndexOutOfBoundsException in class Music due to setCommentAuthor.

Since the comment is retrieve from music by using :
musicToReturn.getComments()
use directly the authorName setter from the comment instead of one more
search in musique.

Remove :

public void setCommentAuthor(Integer index, String authorName) {
log.info("index asked : "+index+" size : "+mComments.size());
Comment comment = mComments.get(index-1);
comment.setAuthorName(authorName);
}

since not used after this change. Use
getComments.get(index).setAuthorName instead which doesn't throw any
IndexOutOfBoundsException.
Merge branch 'ui' of https://github.com/SharUTC/SharUTC into ui