Indexer - Minor - Unable to index local network (ganache) if we forget about ADDRESS_FILE

[paulo-ocean]

If the ADDRESS_FILE is not set AND there is no startBlock defined on RPCS, under certain circumstances we cannot get the contract deployed block.
It will start at block 0 if we cannot get the last deployed block as well
But ... if we can get that last block it is not forced to start from 0... So, without a start block and a contract deployed block... it just doesn't start (Should start at block 0 in this particular case)
Minor, but still needs a tweak