MAGETWO-58316: [Github] Customer Import - Invalid data for insert #4291

Author: Bohdan Korablov

app/code/Magento/CustomerImportExport/Model/Import/Customer.php

@@ -370,11 +370,6 @@ protected function _prepareDataForUpdate(array $rowData)
 
         // attribute values
         foreach (array_intersect_key($rowData, $this->_attributes) as $attributeCode => $value) {
-            if ($newCustomer && !strlen($value)) {
-                $entityRow[$attributeCode] = $value;
-                continue;
-            }
-
             $attributeParameters = $this->_attributes[$attributeCode];
             if ('select' == $attributeParameters['type']) {
                 $value = isset($attributeParameters['options'][strtolower($value)])