Channel solo-ing keyboard shortcut problem

[mstempell]

Used version is 1.7.5

When wanting to play the current track (where the cursor is) solo by pressing CTRL+SHIFT+M, it always mute the first track.
(but then the tracker seems to only take input on the actual track where the cursor was, but which is then muted if it wasn't the first track)

[kometbomb]

Seems like the code is utterly broken. Will fix.