wget: fix autoreconf brokeness

Fix failed AUTORECONF under certain circumstances where gettext infra is
much newer (>= 0.18) than what wget source expects (~ 0.17).
Do this by gettextizing the source before AUTORECONFing.
If this becomes common we may need a FOO_GETTEXTIZE generic option, but
for now this seems to be the only package that needs so. Fixes:
http://autobuild.buildroot.net/results/c0f/c0f7c801f61fdc310cde64342060b00a70155431/



Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Tested-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>