Unstick command can suffocate player

[arcanefeenix]

Brief explanation of issue: Using unstick command, user is sent to spawn but y level 64. If there is terrain there, player will suffocate and die.

Steps to reproduce:

• Make sure there are blocks at spawn ccords > 64
• Unstick player

DiscordChat version: 2.3.0

Minecraft version: 1.12.2