git: needs zlib and host-gettext

host-gettext fixes:
http://autobuild.buildroot.net/results/a5b/a5b1bb708d62a9e296f05899f0984087fcf9e2ce/

zlib fixes:
http://autobuild.buildroot.net/results/08f/08f5ed4dd35ad1ce06dda7577aae87b9aa7069b2/



Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>