Remove file 'metamath.exe' from this git repo
Remove file 'metamath.exe' from this git repo

Metamath.exe is a generated binary file, not part of set.mm,
so I'm removing it.

Signed-off-by: David A. Wheeler <9ae72d22d8b894b865a7a496af4fab6320e6abb2@dwheeler.com>

metamath/set.mm,metamath/set.mm,metamath/set.mm