pass in the flags so libiconv can be found

gettext/gettext.spec

@@ -92,6 +92,8 @@ AutoReqProv:  no
 %build
     CC="%{l_cc}" \
     CFLAGS="%{l_cflags -O}" \
+    CPPFLAGS="%{l_cppflags}" \
+    LDFLAGS="%{l_ldflags}" \
     GREP="grep" \
     ./configure \
         --prefix=%{l_prefix} \