Fix user.bot (#2073)
Fix user.bot (#2073)

* fix user.bot

* user.avatar is nullable (docs)

Drahcirius/discord.js,Drahcirius/discord.js,Drahcirius/discord.js,CodeMan99/discord.js,hydrabolt/discord.js,appellation/discord.js,appellation/discord.js,CodeMan99/discord.js,Lewdcario/discord.js,Lewdcario/discord.js,robflop/discord.js,robflop/discord.js,hydrabolt/discord.js,SpaceEEC/discord.js,Lewdcario/discord.js,appellation/discord.js,SpaceEEC/discord.js,robflop/discord.js,hydrabolt/discord.js,CodeMan99/discord.js,SpaceEEC/discord.js