in note entry mode cmdAddTie() doesn't work in 2nd voice if tied note is in new empty bar - fix attached

1. select an empty bar
2. enter note entry mode: N
3. select 2nd voice: Ctrl-I Ctrl-2
4. enter a note: C
5. add some tied notes: + + +
-> works until measure full
6. try to add some more tied notes
-> won't work, if next measure is empty

expandVoice() is missing in Score::cmdAddTie(). See attached diff

regards,
Friedemann