get_field_sql() has been changed and now it executes
$rs = get_recordset_sql($sql, 0, 1);
to fetch exclusively the first record.
But this has broken compatibility with some old uses where the "LIMIT" clause was being used to enforce only 1 record to be retrieved. To solve this:
1) The function will strip any "LIMIT 1" clause present when invoked (dropping some debug info if found)
2) All the incorrect uses of the function in core will be fixed.
With this, get_fieldXXX() "family" of functions will be cross-db and consistent (always returning 1 value)