Minor reporting fix to contrib/non-profit-audit-reports

This fix is related to Conservancy's specific chart of accounts.  However, there are a number of things in the contrib/non-profit-audit-reports that are somewhat conservancy-specific already, as at least a few of the scripts (summary-reports.plx in particular) are primarily made to just be examples.

Therefore, I'd appreciate if you could merge this in.  Long term, if these scripts were used by others, it would make sense to abstract out the list of regular expressions found in summary-reports.plx into some config file, but since they were already accepted upstream as a hard-coded list, I suggest that we keep the upstream contrib directory matching with what Conservancy is doing -- if for no other reason that I can use this as examples to help answer  ledger questions on IRC, which I do from time to time.