author.icon_url does not work in embed formatted logs

[RedSpid3r]

When using embed format logs, the icon_url for Author does not work:

        VOICE_CHANNEL_JOIN:
          embed: 
            author:
              name: "{member.tag} [{member.id}]"
              icon_url: "{user.avatarURL}"
            description: '<@{member.id}> joined voice channel <#{channel.id}>'
            thumbnail:
              url: '{member.user.avatarURL}'
            color: 0x77dd77 #pastel green
            footer: 
              text: "{timestamp}"

[metal0]

This should be fixed with #395