SAFE_POINT is triggered on removing columns in msa

Scenario to reproduce:

1. Open "data/samples/CLUSTALW/COI.aln".
2. Select the first sequence in the names area.
3. Set focus to the sequence area, click space.
   Expected state: the first sequence is shifted.
4. Call context menu, select {Edit -> Remove column of gaps...}

   menu item.

5. Select the second option (remove by percentage) and accept the dialog.
   Expected state: the first sequence is removed, there are no errors in the log; if the first sequence was reference, the reference is unset.
   Current state: the first sequence is removed, there are errors in the log: "Trying to recover from error: No row ID '1' in an alignment! at src/gobjects/MAlignmentObject.cpp:444".