refactor(reducer): iterate over users in database

and possible fix of 'shadow' users

xp/events.go

@@ -168,5 +168,5 @@ func onDisconnect(s *discordgo.Session, e *discordgo.VoiceStateUpdate, client *r
 func OnLeave(_ *discordgo.Session, e *discordgo.GuildMemberRemove) {
 	utils.SendDebug("Leave event", "user_id", e.User.ID)
 	c := GetCopaing(e.User.ID, e.GuildID)
-	gokord.DB.Delete(c)
+	gokord.DB.Where("guild_id = ?", e.GuildID).Delete(c)
 }