Ignore unsupported exception on setFetchSize

Some databases don't support setFetchSize, such as Apache Phoenix:
https://github.com/apache/phoenix/blob/master/phoenix-core/src/main/java/org/apache/phoenix/jdbc/PhoenixResultSet.java#L784

Older versions of RJDBC seemed to be compatible with Phoenix until 34b45a56163ebe700808349b11b9a36bcfb7b658