/cs amode allows adding a mode that doesn't exist

[eskimo]

I was able to /cs amode #igloo +f eskimo for example, which resulted in the following output:

[11:20:25] -ChanServ- Successfully set persistent mode +f on eskimo
[11:20:25] iglooirc.com sets mode +f eskimo

+f isn't anything according to https://github.com/ergochat/ergo/blob/stable/docs/MANUAL.md#channel-prefixes, however it adds to amode and will keep adding it back on rejoin.

The problem is when doing /cs amode #igloo -f eskimo you'll get this output:

[11:20:31] -ChanServ- Account does not exist

So it can't be removed and doesn't do anything?

[slingamn]

Thanks, opened #2003 for this.