Corrected LONGVARCHAR Field Handling with Fetch Ahead Logic

When marshalling parameters into the SQLDA object for JDBC, c-treeSQL fetch ahead logic inappropriately read a buffer that was allocated one less than required. An off by one error occurred when calculating the start of the field, resulting in the field to be marshalled as a VARCHAR field rather than a LONGVARCHAR. This mismatch generated the internal error (-20000). The length of the allocated buffer has been properly sized now avoiding this error.