DOCS-9890 model-monetary-data: priceDec field -> price

Author: kay-kim

source/tutorial/model-monetary-data.txt

@@ -179,7 +179,7 @@ If you do not want to add a new field with the ``decimal`` value, the
 original field can be overwritten. The following
 :method:`~db.collection.update()` method first checks that ``price``
 exists and that it is a ``long``, then transforms the ``long`` value to
-``decimal`` and stores it in the ``priceDec`` field:
+``decimal`` and stores it in the ``price`` field:
 
 .. code-block:: javascript