Custom script extension workaround for N-1 nodes

Custom script extension workaround for N-1 nodes variable.json

        "tshirtSizeLarge": {
            "storageAccountCount": 5,
            "clusterSizeMinusOne": 4,
            "lastNodeId": 4,
            "clusterSize": 5,
            "couchbaseRamQuota": 88000,
            "vmSize": "Standard_D14",
            "maxNumberOfDataDisksForVmSizeNotUsedButHereForReference": 32,
            "vmTemplate": "[concat(variables('templateBaseUrl'), 'cluster-nodes-D14.json')]",
            "backendIPConfigurations": [{
                "id": "[concat(resourceId('Microsoft.Network/networkInterfaces',  'nic0'),'/ipConfigurations/ipconfig1')]"
            }, {
                "id": "[concat(resourceId('Microsoft.Network/networkInterfaces',  'nic1'),'/ipConfigurations/ipconfig1')]"
            }, {
                "id": "[concat(resourceId('Microsoft.Network/networkInterfaces',  'nic2'),'/ipConfigurations/ipconfig1')]"
            }, {
                "id": "[concat(resourceId('Microsoft.Network/networkInterfaces',  'nic3'),'/ipConfigurations/ipconfig1')]"
            }, {
                "id": "[concat(resourceId('Microsoft.Network/networkInterfaces',  'nic4'),'/ipConfigurations/ipconfig1')]"
            }]
        },
        "vmScripts": {
            "scriptsToDownload": [
                "[concat(variables('templateBaseUrl'), 'couchbase-azure-install.sh')]",
                "[concat(parameters('cbPackageDownloadBase'), parameters('cbPackage'))]",
                "[concat(variables('sharedBaseUrl'), 'vm-disk-utils-0.1.sh')]"
            ],
            "installCommand": "[concat('bash couchbase-azure-install.sh -d ', parameters('cbPackage'), ' -n ', parameters('clusterName'), ' -i ', concat(variables('networkSettings').nodesIpPrefix, '-', variables('clusterSpec').clusterSize), ' -a ', variables('machineSettings').adminUsername, ' -p ', variables('machineSettings').adminPassword, ' -r ', variables('clusterSpec').couchbaseRamQuota)]",
            "setupCommand": "[concat('bash couchbase-azure-install.sh -d ', parameters('cbPackage'), ' -n ', parameters('clusterName'), ' -i ', concat(variables('networkSettings').nodesIpPrefix, '-', variables('clusterSpec').clusterSize), ' -a ', variables('machineSettings').adminUsername, ' -p ', variables('machineSettings').adminPassword, ' -r ', variables('clusterSpec').couchbaseRamQuota, ' -l')]"
        },