SkinTexture broke using hash

Summary

Describe the bug encountered in detail.

Steps to reproduce

• use latest dev (v5.7.0-SNAPSHOT/5093) (worked fine before until stable 5.6.1)
• creating equipment in MythicMobs/items/ship.yml https://mclo.gs/wX6uTkp (tried also Id: player_head with no success)
• set as equipment for a mob https://mclo.gs/3iqhxDv

Current behavior

• player head stays at default/steve

Intended correct behavior

player head will use correct skin