4892: ContentDAO.isFieldsValid() return value should not be tied to $msg->containsErr...

4892: ContentDAO.isFieldsValid() return value should not be tied to $msg->containsErrors()

This function would erroneously return 'false' if the $msg array contained errors prior to
entry into the function. This sometimes caused unexplained IMS CC import failures when
inserting new lessons into the database.

Use a local return result to ensure accurate result.