Alternative test for dpkg multiarch support in lxc-debian template

Signed-off-by: David Noyes <david.j.noyes@gmail.com>

templates/lxc-debian.in

@@ -377,13 +377,9 @@ EOF
 
     # If the container isn't running a native architecture, setup multiarch
     if [ "${arch}" != "${hostarch}" ]; then
-        mkdir -p ${rootfs}/etc/dpkg/dpkg.cfg.d
-        echo "foreign-architecture ${hostarch}" > ${rootfs}/etc/dpkg/dpkg.cfg.d/lxc-multiarch
-
         # Test if dpkg supports multiarch
-	if chroot $rootfs dpkg -l dpkg 2>&1 | grep -q "unknown option 'foreign-architecture'"; then
-	    echo "dpkg does not support multiarch: removing multiarch configuration file"
-            rm ${rootfs}/etc/dpkg/dpkg.cfg.d/lxc-multiarch
+        if ! chroot $rootfs dpkg --print-foreign-architecture 2>&1; then
+            chroot $rootfs dpkg --add-architecture ${hostarch}
         fi
     fi