Bug 17289: Holds awaiting pickup shows date unformatted

Bug 17289: Holds awaiting pickup shows date unformatted

In the Staff client, under Circulation -> Circulation reports,
the date shown in the heading of the 'Holds awaiting pickup'
report is not formatted according to the 'dateformat' system
preference.

This (trivial) patch fixes that.

Test plan:
1) In the Staff client, go to Circulation and under 'Circulation
   reports' click on 'Holds awaiting pickup'
   (cgi-bin/koha/circ/waitingreserves.pl).
2) Observe that the date shown in the heading is always formatted as
   yyyy-mm-dd regardless of the value of the 'dateformat' syspref.
3) Apply the patch.
4) Re-visit the 'Holds awaiting pickup' report. Confirm that the patch
   worked, i.e. the date shown in the heading is formatted according
   to the 'dateformat' system preference.

Signed-off-by: Hector Castro <hector.hecaxmmx@gmail.com>
Works as advertised

Signed-off-by: Katrin Fischer  <katrin.fischer@bsz-bw.de>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
(cherry picked from commit f9e3639da7ef02a6ca08014179d216e1d938a401)
Signed-off-by: Frédéric Demians <f.demians@tamil.fr>