Non-existing user/group can be added by user/group suggest

Steps to reproduce:
1. Create with AWM a new application with 2 fields: users and groups
2. Create new entry in the new application
3. Write some random text in the user input and "User not found" will be displayed
4. Write some random text in the group input and "Group not found" will be displayed
5. With these 2 values in the inputs, save the document.

Result: Even if the written user and group are not existing, the values are displayed.