Prevent stripping Id field to fix update()

Author: simonharris

src/Phpforce/SoapClient/Client.php

@@ -665,7 +665,7 @@ protected function createSObject($object, $objectType)
 
         foreach (get_object_vars($object) as $field => $value) {
             $type = $this->soapClient->getSoapElementType($objectType, $field);
-            if (!$type) {
+            if ($field != 'Id' && !$type) {
                 continue;
             }