(fix) Update -n to -k in the getopts string for correct handling

[elijah0kello]

What is the relevance of this change ?

[Abhinavcode13]

case "${OPTION}" in
            m)      mode_opt="${OPTARG}"
            ;;
            k)      k8s_distro="${OPTARG}"
            ;;
            d)      debug="${OPTARG}"
            ;;
            a)      apps="${OPTARG}"
            ;;
            f)      fineract_instansces="${OPTARG}"
            ;;
            e)      environment="${OPTARG}"
            ;;
            v)      k8s_user_version="${OPTARG}"
            ;;
            u)      k8s_user="${OPTARG}"
            ;;
            h|H)    showUsage

Here in the previous version there was no option related to n specifically.