Always use the trie's fork block number, as it might be different (li…

…ke in trace transaction)

lib/utils/forkedblockchain.js

@@ -330,7 +330,7 @@ ForkedBlockchain.prototype.getLookupAccount = function(trie) {
           callback(null, account);
         });
       } else {
-        this.fetchAccountFromFallback(address, to.number(this.forkBlockNumber), callback);
+        this.fetchAccountFromFallback(address, to.number(trie.forkBlockNumber), callback);
       }
     });
   };