DB/Characters: Remove guildId from characters table (characters_database.sql only)

This field was dropped long ago in 1a290f17f59943905bec7dd413c4879b4bbf6f8e

Thanks to Aokromes for spotting the issue
Merge branch '4.3.4' of https://github.com/TrinityCore/TrinityCore into TrinityChat4.3.4