Bug 26982: Typo in system preference UsageStats: statisics

Bug 26982: Typo in system preference UsageStats: statisics

Test Plan:
1. Go to Administration
2. Go to System Preferences
3. Go to Administration (on the right)
4. At the bottom, under 'Share anonymous usage statistics', find
UsageStats
5. In the value box, the bottom line should say 'statisics' instead of
'statistics'
6. Apply the patch
7. Repeat steps 1-4
8. In the value box, the bottom line should now say 'statistics'

Signed-off-by: Sally <sally.healey@cheshiresharedservices.gov.uk>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>