midish does not exit on EOF/end of script

Hello,

I noticed that midish 1.4.0 does not stop on the end of the script,
while it used to in older versions.
That's when running using midish -b
As a workaround I add "exit" as the last command.

I saw it when trying to run the tests, it would block. I've patched it
like this:

https://github.com/iwanb/nixpkgs/commit/75acc4ceafa116f5e5812e85dbc4fac7f2bf4f58#diff-8cffa2788389eaf00c8a41cb45de4816ced320731176205edb1759c81102becf

Similarly the smfplay and smfrec scripts require two Ctrl+C to exit,
I've also added exit there explicitly.

Cheers,
Iwan