package/hiredis: install alloc.h
This will fix build of collectd, proftpd ... with latest hiredis
Fixes:
- http://autobuild.buildroot.org/results/f5afe60defd63461a5fc06b26bd4759fb5f56a8f
- http://autobuild.buildroot.org/results/45e980c85d170827d3a41e7443cf1088b2d59ead
Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
(cherry picked from commit b72be8c48b7c110f5e63e741599ceca1d0352fbc)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>