Sheeps eat grass when MobGriefing is set to false

There are already old reports concerning this issue but it is still a thing. (MC-147444)

I tested it in singleplayer 1.14.3 with mobGriefing = false

The sheeps eat the grass and the grass dont dissapear.

With this bug it is possible to create op wool-farms when the gamerule is set to false!