Bug 23685: (follow-up) Control ODS exporting

Bug 23685: (follow-up) Control ODS exporting

The pref ReportsExportFormatODS should be true for exporting
to ODS in Reporting.

Test plan:
Set pref to false value.
Check if option is no longer available on report's Download menu.
Manipulate URL with op=export&format=ods. No data expected.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>