Incorrect settings after reopening "Pairwise Alignment" tab

Regression: UGENE-1668 can be reproduced.

Affected tests:

• GUITest_regression_scenarios_test_1668
• GUITest_common_scenarios_options_panel_MSA_save_parameters_test_0003_1
• GUITest_common_scenarios_options_panel_MSA_save_parameters_test_0003_1

Scenario:

1. Open "samples/CLUSTALW/COI.aln"
2. Open the "Pairwise Alignment" tab on the Options Panel.
3. Select "Phaneroptera_falcata" as the first sequence.
4. Select "Isophya_altaica_EF540820" as the second sequence.
5. Close the "Pairwise Alignment" tab.
6. Open the "Pairwise Alignment" tab.
   Expected state: the chosen sequences and their order are saved.
   Actual state: "Isophya_altaica_EF540820" became the first one. "Phaneroptera_falcata" disappeared.