Corrected Error 17466 on Index Creation

An error 17466 (CT - Incremental Index - dfilno not a ISAM file) was observed when adding an index in c-treeACE SQL. During a pending delete an internal file control block member could be found in an unexpected state when re-used, as in this case, by an index creation. This internal flag is now explicitly set for any pending delete to avoid this error.