[PATCH 0/1 conductor] BZ 811639 - 'No users selected' error when change the same Role Assignment in two different browsers

[Tzu-Mainn Chen]

This issues pops up during a permission multi_update, which can only happen 
when user(s) exist.  The multi_update will iterate through every user; thus, 
the message is inaccurate.  I've changed the error to a more sedate notice.

Mainn