Bug 9394: QA Followup

Bug 9394: QA Followup

* C4::Reserves::_FixPriority
  - The previous code checked the cancellationdate. If think you never pass
in it with bad parameters, but in order to be sure I added the check on
this value.
  - The reservedates array was never used.

* circ/circulation.tt
There was a bug: it was not possible to remove an hold from the
circulation page. Passing reserve_id fixes the issue.

* C4::Reserves::GetReserveId
This subroutine did not have a unit test.

Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>
Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>