gmp: fix stupid host/build detection in configure script on i386.

--HG--
extra : convert_revision : f804f3d494ac110600b987cf96bcb6f151e16d9c

templates/gmp.tmpl

@@ -23,3 +23,11 @@ long_desc="
 
 base_chroot=yes
 run_depends="glibc-2.8"
+
+pre_configure()
+{
+	if [ "$xbps_machine" != "x86_64" ]; then
+		local triplet="$xbps_machine-pc-linux-gnu"
+		configure_args="--host=$triplet --build=$triplet"
+	fi
+}