simplify check for --local

weave

@@ -703,7 +703,7 @@ case "$COMMAND" in
         ;;
     run)
         [ $# -gt 0 ] || usage
-        if [ "$LOCAL" = "--local" ]; then
+        if [ -n "$LOCAL" ]; then
             dns_args "$@"
         else
             DNS_ARGS=$(exec_remote dns-args "$@")
@@ -712,7 +712,7 @@ case "$COMMAND" in
         collect_cidr_args "$@"
         shift $CIDR_COUNT
         CONTAINER=$(docker run $DNS_ARGS -d "$@")
-        if [ "$LOCAL" = "--local" ]; then
+        if [ -n "$LOCAL" ]; then
             create_bridge
             with_container_netns $CONTAINER attach $CIDR_ARGS >/dev/null
             tell_dns PUT $CONTAINER $CIDR_ARGS