Crash on assert while using the Smith-Waterman algorithm with incorrect matrix.

1. Open "_common_data/fasta/fa1.fa".
2. Click "Smith-Waterman search" on the toolbar.
3. Set any pattern without symbol "T".
4. Select scoring matrix "rna".
5. Start search.
Assertion will not pass: unexpected symbols in sequence.
This matrix is not for the dna alphabet, it shouldn`t shown in the dialog.
There is no crash in release version, but it doesn't allow to use the symbol "T".