Merge branch '18225-avoid-full-table-users-count' into 'master'

Check if the Users table has exactly one user limiting the whole set

## What does this MR do?

Limit the query set so about a full scan for all the rows on the users table (only scan to records)

#18225 

See merge request !4492

app/controllers/sessions_controller.rb

@@ -40,7 +40,7 @@ class SessionsController < Devise::SessionsController
   # Handle an "initial setup" state, where there's only one user, it's an admin,
   # and they require a password change.
   def check_initial_setup
-    return unless User.count == 1
+    return unless User.limit(2).count == 1 # Count as much 2 to know if we have exactly one
 
     user = User.admins.last