- Don't call SQLGetDiagRec() automatically on SQL_ERROR, some ODBC
seem to have a broken SQLGetDiagRec() implementation. Let user call
SQLGetDiagRec() from Scheme at his own risk.
The ODBC documentation thinks it's a good idea to call SQLGetDiagRec()
after each ODBC-call that might return SQL_SUCCESS_WITH_INFO. IMHO
this sucks. However it's now possible to do so in the user's Scheme
code.