[1.1] Deleting/moving remaining tie from note in a deleted system causes crash

1. Open attached score.
2. Drag-select bar 2, but exclude the ties.
3. 'Delete Selected Measures'.
4. Click a tie.
5. Delete.

Result: Crash.

Discussion: Moving the tie after step 3 also causes a crash. It's not an issue in the trunk, however: #11898: [Trunk] Ties don't delete upon select all or clicking bar

Using MuseScore 1.1 - Mac 10.6.8.