Feature request: Don't show solution if the same letters are set twice.

[f00ale]

In the current version the solution to the previous puzzle is shown when new letters are set.
However, if one - by mistake - invoke the !setnian command with the same letters twice the solution is spoiled.
My suggestion is that the !setnian command should check if the new letters match the ones already set, and silently ignore if that is the case.