Bug 8008 - Fix typo in man page for koha-create

Bug 8008 - Fix typo in man page for koha-create

Line 121 had "/etc/koha/koha-site.conf" instead of "/etc/koha/koha-sites.conf"

To test:
I don't think this needs any actual testing, just read the patch and check
that it looks sensible...

Signed-off-by: Marc Veron <veron@veron.ch>
Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>
Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>