Bug 12728: Add StatisticsFields to sysprefs.sql

Bug 12728: Add StatisticsFields to sysprefs.sql

Bug 7955: [Statistics tab for Patron checkouts] introduced the pref
StatisticsFields but did not add it to the sql install file.

Test plan:
Run webinstaller or mysql ... < sysprefs.sql
Verify that the new pref is in your systempreferences table.

Signed-off-by: Bernardo Gonzalez Kriegel <bgkriegel@gmail.com>
Run webinstall, new syspref loaded.
No koha-qa errors.

Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>