When deleting/modifying the user in a direct message, the styling for label conflict is not always updated

[douglasrapp]

When creating a direct message, if a security label is selected that causes a conflict with the chosen user, that user text is styled red. However, upon selecting that field and editing the target user, any label-related warnings are not updated until an option is selected in a drop-down list.

Steps to reproduce:

1. Log in as 'testuser1'
2. Create new direct message
3. In the 'with whom' dialog, enter 'testuser3'
4. Add any SCI/SAP label - the 'testuser3' entry should now turn red
5. Place the cursor in the 'with whom' field and start editing with the keyboard (e.g., hit backspace to remove the '3' from 'testuser3')
6. At this point, the remaining text for the target user is still red, and all other warnings still remain.

[douglasrapp]

Related to #64