Added default values if there are no bans/unbans yet.

50-fail2ban

@@ -8,6 +8,8 @@ out=""
 for jail in ${jails[@]}; do
     bans=$(printf -- '%s\n' "${lines[@]}" | grep -iP "[[:digit:]]+ \[$jail\] ban" | awk '{print $1}')
     unbans=$(printf -- '%s\n' "${lines[@]}" | grep -iP "[[:digit:]]+ \[$jail\] unban" | awk '{print $1}')
+    bans=${bans:-0} # default value
+    unbans=${unbans:-0} # default value
     diff=$(($bans-$unbans))
     out+=$(printf "$jail, %+3s bans, %+3s unbans, %+3s active" $bans $unbans $diff)"\n"
 done