Bugfix: avoid ~bdb_blockchain() body if initialisation never had a chance to start.
Bugfix: avoid ~bdb_blockchain() body if initialisation never had a chance to start.

BWallet/libbitcoin,libmetrocoin/libmetrocoin-consensus,Airbitz/libbitcoin,libmetrocoin/libmetrocoin-consensus,libtetcoin/libtetcoin-consensus,BWallet/libbitcoin,Airbitz/libbitcoin,libmetrocoin/libmetrocoin-consensus,kaostao/libbitcoin,libtetcoin/libtetcoin-consensus,Airbitz/libbitcoin,GroestlCoin/libgroestlcoin,kaostao/libbitcoin,BWallet/libbitcoin,swansontec/libbitcoin,libmetrocoin/libmetrocoin-consensus,libmetrocoin/libmetrocoin-consensus,GroestlCoin/libgroestlcoin,GroestlCoin/libgroestlcoin,BWallet/libbitcoin,libtetcoin/libtetcoin-consensus,Airbitz/libbitcoin,kaostao/libbitcoin,swansontec/libbitcoin,kaostao/libbitcoin,swansontec/libbitcoin,libtetcoin/libtetcoin-consensus,GroestlCoin/libgroestlcoin,swansontec/libbitcoin,libtetcoin/libtetcoin-consensus