Bug 14291: Fix OpacExportOptions text

Bug 14291: Fix OpacExportOptions text

This patch removes the instruction to separate values by | in the
OpacExportOptions preference.

To test:

Go to system preferences
Find OpacExportOptions
Confirm text is right

Signed-off-by: Indranil Das Gupta (L2C2 Technologies) <indradg@gmail.com>
Test output compliant with expected test plan outcome.

Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Changed "List" to "Select" and removed a space before the : at the end.
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>