build system updated

build-in-docker.sh

@@ -295,7 +295,7 @@ case "$mode" in
             docker exec ${DOCKER_ID} bash -c "echo 'Pin-Priority: -100' >> /etc/apt/preferences"
             docker exec ${DOCKER_ID} bash -c "echo >> /etc/apt/preferences"
         done
-        if test -n "${keys[@]}"; then # fix dependency bug in cosmic and stretch
+        if test -n "${keys[*]}"; then # fix dependency bug in cosmic and stretch
             docker exec ${DOCKER_ID} apt-get install ${OPTIONS} ${PREVENT// /- }- gnupg
             for key in "${keys[@]}"; do
                 wget -O- "$key" \