respect the configure nls flag

http://bugs.gentoo.org/192819

--- man/Makefile.in
+++ man/Makefile.in
@@ -223,7 +223,11 @@
 top_srcdir = @top_srcdir@
 
 # Extract the list of languages from the po4a config file.
+ifeq ($(USE_NLS),yes)
 LINGUAS = $(shell sed -ne 's/^.*\[po4a_langs\] \(.*\)$$/\1/p' $(srcdir)/po/po4a.cfg)
+else
+LINGUAS =
+endif
 dist_man_MANS = \
 	822-date.1 \
 	cleanup-info.8 \