Update time it takes to seed database

doc/development/database_debugging.md

@@ -19,7 +19,7 @@ If you just want to delete everything and start over with an empty DB (~1 minute
 
 - `bundle exec rake db:reset RAILS_ENV=development`
 
-If you just want to delete everything and start over with dummy data (~40 minutes). This also does `db:reset` and runs DB-specific migrations:
+If you just want to delete everything and start over with dummy data (~4 minutes). This also does `db:reset` and runs DB-specific migrations:
 
 - `bundle exec rake dev:setup RAILS_ENV=development`