Fix Message Link Embeds on @me guilds

[VillainsRule]

this fixes bots such as Make a Quote attempting to use @me as a guild, which discord supports (for some reason).
my method for the guildID var was a bit hacky, but there seem to be strict const/let structures.

this is my first time contributing, so lmk if i did something wrong

[Vendicated]

This makes no sense. @me is the "guild" id for private channels. links with @me point to messages in some private channel

if your link contains @me as guild id and the id of some guild channel, it is simply not a valid message link.

[Vendicated]

bc0a550

[VillainsRule]

It makes no sense to me either, but it seems like if @me is the guild it searches for channels in existing ones.

https://discord.com/channels/GUILD_ID/456787654567876/45678754567656789 and https://discord.com/channels/@me/456787654567876/45678754567656789 have the same effect.

I checked, it does redirect.