database_fixture.cpp:  Fix integer overflow bug waiting for zero blocks #559
database_fixture.cpp:  Fix integer overflow bug waiting for zero blocks #559

cryptonomex/graphene,abitmore/bitshares-2,peertracksinc/muse,abitmore/bitshares-2,oxarbitrage/bitshares-core,bitsuperlab/cpp-play2,bigoc/openchain,bigoc/openchain,pmconrad/graphene,bitsuperlab/cpp-play2,bigoc/openchain,abitmore/bitshares-2,bigoc/openchain,bitshares/bitshares-2,pmconrad/graphene,peertracksinc/muse,peertracksinc/muse,cryptonomex/graphene,abitmore/bitshares-2,bitshares/bitshares-2,peertracksinc/muse,cryptonomex/graphene,oxarbitrage/bitshares-core,oxarbitrage/bitshares-core,pmconrad/graphene,bitsuperlab/cpp-play2,bitshares/bitshares-2,oxarbitrage/bitshares-core,bitshares/bitshares-2,pmconrad/graphene