Zombie Pigmen become hostile to trident if thrown by dispenser

When a trident threw by a dispenser hurt a zombie pigman, it will hostile the trident.

Here are steps to reproduce it:

1. Use spawn eggs to spawn a zombie pigman(Spawn naturally also works).

2. Place a dispenser and put a trident in it.

3. Active the dispenser, if the trident hurt the zombie pigman, the zombie pigman will hostile the trident.