[MU3] Fix #318034: Make Harmonium SND capable.

[Jojo-Schmitz]

Reed Organ is, and is (basically) the same instrument.

Resolves: https://musescore.org/node/318034

See discussion on Telegram too: https://t.me/musescoreeditorchat/104446

Same should go to master too, see #7607

[vpereverzev]

merged in master

[Jojo-Schmitz]

Needed on 3.x too though.
Is closing this here the penalty for me having done the port to master myself?

[vpereverzev]

Of course it's not
I was aimed to merge in 3.x only those changes that we still need to port in master. But actually, there is no harm to "just" merge it in 3.x and then port only "libmscore" changes, so maybe I was in a hurry with this

[Jojo-Schmitz]

I thought so, but felt like being punished ;-)

[vpereverzev]

I thought so, but felt like being punished ;-)

Yeah, sorry for that, I'm going to take another look on PRs that have been closed during this day. I guess we can merge them, just in case