E1450. UI change for assignment view

I submitted pull request 2 days ago, but updated some codes after that. Let me know if I need to submit a pull request again.
I commentted this because this will make setting rounds number 2 in Due Dates tab ineffective (which will always automatically turn 3), and I couldn't solve it unless I comment these lines. If this change will have an impact on the other part of the system, please let me know.