reduce number of warning messages when building docs
reduce number of warning messages when building docs

Warnings were emitted for every info file (twice) instead of once.

ledger/ledger,paulbdavis/ledger,jwakely/ledger,duncanmortimer/ledger,ledger/ledger,jwakely/ledger,paulbdavis/ledger,duncanmortimer/ledger,jwakely/ledger,paulbdavis/ledger,afh/ledger,afh/ledger,afh/ledger,afh/ledger,duncanmortimer/ledger,jwakely/ledger,duncanmortimer/ledger,paulbdavis/ledger,ledger/ledger,jwakely/ledger,paulbdavis/ledger,jwakely/ledger,jwakely/ledger,ledger/ledger,paulbdavis/ledger,paulbdavis/ledger,duncanmortimer/ledger,ledger/ledger,duncanmortimer/ledger,afh/ledger,duncanmortimer/ledger