Problem: Import fails with accents in speaker names

[jrwdunham]

To recreate:

1. create a .csv file containing a new speaker name with accents
2. open the file to import it into Dative
3. click the button to validate the csv file
4. click the create speaker button
5. Dative will create the speaker and notify you about it
6. click the button to validate again
7. Dative will still say Warning: "Unable to use “...” as a value for speaker"