Bug 13747: Fix problems with frequency descriptions containing quotes

Bug 13747: Fix problems with frequency descriptions containing quotes

If a serial frequency description contains quotes or is surrounded by
quotes, the description is empty ("TEST" > empty) or shown without the
quotes part (TEST "sth" > TEST) on editing the frequency.

To verify:
- Create a new frequency with description: "Test"
- Modify frequency
- Verify the description field is empty

To test:
- Apply patch
- Try to recreate, verify that the description field is
  correctly filled when editing
- Test also with a name like: 'A "souble quoted" name'

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>