Bug 20949: Koha depends on Clone

Bug 20949: Koha depends on Clone

Clone was not declared a dependency before. It used to be a dependency
of Hash::Merge but isn't in the recent version.

Signed-off-by: Mirko Tietgen <mirko@abunchofthings.net>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
(cherry picked from commit f1a54e09d99eea391b71ceafc291cbca8c838da2)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>