Description:

When a user which is part of a group is added in the same group then it shows that "Users have been added."
But it should show that the user already exists in the group.

Steps to reproduce:

1. Go to add user option
2. Type the user name
3. It shows the same message if the user already exists in the group or not.

Expected behavior:

If a user is not part of the group then it should show the message that the user has been added.
If a user is part of the group then it should show the message that the user already exists in the group.

Actual behavior:

The same message is shown if a user is part of a group or not when he/she is added.