Bug 10240: (follow-up) don't delete transactions if auth fails

Bug 10240: (follow-up) don't delete transactions if auth fails

When uploading transactions, we were not checking that authentication
had succeeded before deleting the transactions from the local database.
That was bad. With this patch, we check. That is good.

Signed-off-by: Bernardo Gonzalez Kriegel <bgkriegel@gmail.com>
Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>
Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>