Command "/ gamerule" non-existent game rules is displayed erroneously been changed

At the command "/ gamerule", a non-existent game rules have been modified. And, it is false indications.

I think that it should be displayed this way
"This game rule does not exist." And, you should be displayed.

Happened bug:
When you execute, "the game rules [non-existent game Rule name was updated to [quantity]. And, are displayed.

Steps to Reproduce:
・ Implanting "/ gamerule [non-existent game rules] [quantity]" in the chat field