message: Fixed CellValue::coerceToTimestamp() throwing not returning null
diff: @@ -703,7 +703,12 @@ coerceToTimestamp() const
  if (type == ST_EMPTY)
  return Date::notADate();
  if (isAsciiString()) {
  + try {
  + MLDB_TRACE_EXCEPTIONS(false);
  return Date::parseIso8601DateTime(toString());
  + } MLDB_CATCH_ALL {
  + return CellValue();
  + }
  }
  if (type == ST_TIMESTAMP)
  return *this;
  