Same here - just remove this and go with the default. This is an optimization which determines whether or not the scan start/stop key can be formed with a row key column using this function.  For example:
SELECT * FROM my_table WHERE upper(host) = 'N'
If we allow this to be used to form the start/stop row key, then you'd end up with a scan like this:
SCAN from 'N' inclusive to 'N' exclusive
But then we'd miss rows where host = 'n'
We could become smarter about this down-the-road and form two scans like this:
SCAN from 'N' inclusive to 'N' exclusive
SCAN from 'n' inclusive to 'n' exclusive
and concatenate the results, but we don't have this functionality yet.