syntax and readability

minifirewall

@@ -100,14 +100,14 @@ is_ipv6_enabled() {
 is_docker_enabled() {
     test "${DOCKER}" = "on"
 }
-
 chain_exists() {
-    local chain_name="$1" ; shift
-    [ $# -eq 1 ] && local intable="--table $1"
+    chain_name="$1"
+    if [ $# -ge 2 ]; then
+        intable="--table $2"
+    fi
     # shellcheck disable=SC2086
     iptables ${intable} -nL "${chain_name}" >/dev/null 2>&1
 }
-
 source_file_or_error() {
     file=$1
     echo "...sourcing '${file}\`"
@@ -233,7 +233,6 @@ start() {
     # ${IPT} -t NAT -I PREROUTING -s ${LOOPBACK} -i ! lo -j DROP
     ${IPT} -A INPUT -s ${LOOPBACK} ! -i lo -j DROP
 
-
     if is_docker_enabled; then
         ${IPT} -N MINIFW-DOCKER-TRUSTED
         ${IPT} -A MINIFW-DOCKER-TRUSTED -j DROP