Unity 2018 and VRCSDK2 fix for iwsd_vrc Emu_Trigger.

[lyuma]

Unity 2018 no longer supports serialization of components such as VRC_Trigger, used by DeepCopy.

However, as of VRCSDK2, the VRC_Trigger components are no longer destroyed, so a DeepCopy is no longer necessary. Therefore, we can safely reference the trigger list from the original component as a workaround.