Bug 15029: Make the IssueSlip tests pass even if launched after 23:00

Bug 15029: Make the IssueSlip tests pass even if launched after 23:00

Prior to this patch, the tests did not pass if they were launched after
23:00.
DateTime complains if you ask for creating a date with hour => 24 (which
is logical so far).

Test plan:
0/ Don't apply this patch
1/ sudo date -s "2015-10-19 23:50:00";prove
t/db_dependent/Members/IssueSlip.t
2/ Apply this patch and repeat 1.

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>